02 de julio de 2022

Dioscoreas of the Southern Cape

Ludwig Muller
ludwigxem@gmail.com

@outramps-tanniedi @nicky @jeremygilmore this article is a not complete yet- I'll need to consult Herbarium references- but it'll work for now.

According to Di Turner (pers. comm.) the Dioscoreas of the Garden Route are difficult to identify- at least, to species level. This article aims to clear up the confusion surrounding this cryptic genus with regard to the populations in the Garden Route area, which is defined as the region south of the Kammanassie mountains, west of Harkerville and east of Herbertsdale.
Dioscorea hemicrypta is here treated as the same species as D. elephantipes.

Dioscorea sylvatica Eckl.
iNat holotype: https://www.inaturalist.org/observations/118894140
iNat paratype: https://www.inaturalist.org/observations/122810662

Dioscorea mundii Baker
iNat holotype: https://www.inaturalist.org/observations/16318758
iNat paratype: https://www.inaturalist.org/observations/13581613

Dioscorea burchellii Baker
iNat holotype: https://www.inaturalist.org/observations/91632981
iNat paratype: https://www.inaturalist.org/observations/18062864

Dioscorea elephantipes (hemicrypta) (L'Her) Engl.
iNat holotype: https://www.inaturalist.org/observations/10925084
iNat paratype: https://www.inaturalist.org/observations/11081393

Key:

  • 1. N of the Outeniquas. Leaves pale blue/turquoise....... D. elephantipes/hemicrypta complex
    -Leaves green....... 2

  • 2. Leaves shallowly cordate at base....... D. burchellii
    -Leaves deeply cordate....... 2

  • 3. Leaves deeply incised, edges slightly concave, appearing very shallowly trilobed....... D. sylvatica
    -Leaf edges more convex than otherwise....... D. mundii

Projects worth joining if you found this article interesting:
https://www.inaturalist.org/projects/lianes-and-creepers-of-the-southern-cape-and-little-karoo

References:
burchellii- http://redlist.sanbi.org/species.php?species=1777-3
https://plants.jstor.org/compilation/Dioscorea.burchellii

sylvatica- http://redlist.sanbi.org/species.php?species=1777-4002
http://www.bihrmann.com/caudiciforms/subs/dio-syl-sub.asp
https://plants.jstor.org/compilation/Dioscorea.sylvatica

elephantipes- http://redlist.sanbi.org/species.php?species=1777-12
https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:317936-1

(elephantipes) hemicrypta- http://redlist.sanbi.org/species.php?species=1777-13

mundii- http://redlist.sanbi.org/species.php?species=1777-18
https://plants.jstor.org/stable/10.5555/al.ap.flora.floc015585

Ingresado el 02 de julio de 2022 por ludwig_muller ludwig_muller | 0 comentarios | Deja un comentario

20 de abril de 2022

Epiphytic orchids in the Southern Cape: Identification by leaf

@milewski @jeremygilmore @justinponder2505 @christiaan_viljoen @malthinus @brendancole

By Ludwig Muller, SCHG (Southern Cape Herbarium, George)
ludwigxem@gmail.com

What are epiphytic orchids?
Epiphytic is best explained here: https://www.merriam-webster.com/dictionary/epiphyte
Basically, it's a plant growing on another plant without being parasitic. The host plant is normally larger than the epiphyte.
Most people, if they think of orchids at all, think of the epiphytic orchids. But here in the Southern Cape the majority of orchids are geophytes/terrestrial.
We are only supposed to have 9 species of epiphytic orchids here, but apparently Aerangis mystacidii has been reported from George and Knysna. Due to a paucity of recent records this species has been excluded, but can be seen here: https://www.inaturalist.org/observations/84737527 and https://www.inaturalist.org/observations/70134699 . Tridactyle bicaudata subsp. rupestris is not included in this article because it never grows on trees. The orchids listed here normally occur in dense Afrotemperate forest, and sometimes in coastal thicket.

The species list, with type specimens, is as follows:
Angraecum conchiferum- https://www.inaturalist.org/observations/99573537
A. pusillum- https://www.inaturalist.org/observations/10798465
A. sacciferum- https://www.inaturalist.org/observations/69713856
Cyrtorchis arcuata subsp. arcuata- https://www.inaturalist.org/observations/102243416
Calanthe sylvatica- https://www.inaturalist.org/observations/71129824
Liparis remota- https://www.inaturalist.org/observations/78057117
Mystacidium capense- https://www.inaturalist.org/observations/96900170
Polystachya ottoniana- https://www.inaturalist.org/observations/10859440
Tridactyle bicaudata subsp. bicaudata- https://www.inaturalist.org/observations/68215956
Note: Liparis remota and Calanthe sylvatica are normally terrestrial. However, you do find the odd specimen growing epiphytically, which is why they're included here.

Now that you know what the local orchids look like, we can deal with imposters.
Firstly, the fern Vittaria isoetifolia can be confused with Angraecum pusillum.
See https://www.inaturalist.org/observations/20291984 and compare with Angraecum observation above.

Next is Lepisorus schraderi, another epiphytic fern. It also grows as a lithophyte on occasion.
https://www.inaturalist.org/observations/68878068
https://www.inaturalist.org/observations/10822306
Compare with Mystacidium and young Cyrtorchis.

Pleopeltis macrocarpa could possibly be identified as an orchid.
https://www.inaturalist.org/observations/77108790

Elaphoglossum ferns are great candidates for confusion. See below:
https://www.inaturalist.org/observations/75070759
https://www.inaturalist.org/observations/103881674
https://www.inaturalist.org/observations/109748996

And finally the Paintbrush lily,Scadoxus puniceus. It sometimes grows as an epiphyte, notably the population on Hoekwil Big tree. See https://www.inaturalist.org/observations/107958850
Scadoxus is distinguished from epiphytic orchids by the purplish-black spots on the lower stem.

All epiphytic ferns can be distinguished from orchids by the lack of long, whitish roots clasping the host.

And now we can move on to identifying the orchids themselves.
As before, I have prepared a key. I think it's foolproof, but if you run into any hitches please let me know.

Leaves less than or equal to 8mm wide....... 1.1
Leaves greater than 8mm but less than or equal to 12mm in width....... 2.1
Leaves greater than 12mm wide....... 3.1

  • 1.1 Sympodial growth pattern/pseudobulbs present....... Polystachya ottoniana
    -Monopodial growth pattern/pseudobulbs absent....... 1.2

  • 1.2 Leaves at least 10 times longer than wide, grass- like, in a terminal cluster....... Angraecum pusillum
    -Leaves not grass- like....... 1.3

  • 1.3 Leaf margins not rolled / leaf V-shaped in cross section, stem to 350mm....... Tridactyle bicaudata
    -Leaf margins rolled ever so slightly, stems to 300mm....... 1.4

  • 1.4 Plant compact, stem less than or equal to 40mm, 4-8 leaves....... Angraecum sacciferum
    -Plant branching, stem less than or equal to 300mm, 8-16 leaves.......Angraecum conchiferum

  • 2.1 Leaf with prominent apical "V", stem less than or equal to 350mm....... Tridactyle bicaudata
    -Leaf lacking prominent "V", stem to 25mm....... Mystacidium capense

  • 3.1 Leaves pleated....... 3.2
    -Leaves bilobed....... 3.3

  • 3.2 Leaves less than or equal to 100mm long....... Liparis remota
    -Leaves greater than 190mm long....... Calanthe sylvatica

  • 3.3 Leaves with prominent apical "V", stem to 400mm....... Cyrtorchis arcuata
    -Leaves lacking prominent "V", stem to 25mm max....... Mystacidium capense

Terminology:
Sympodial growth- https://myfirstorchid.com/2016/07/04/monopodial-and-sympodial-orchids/
Leaf margins rolled- https://woodyplantstutorial.nres.illinois.edu/margins/mar-revolute.html
Apical "V"- a V-shaped indentation at the leaf tip
Pleated leaves- see first image at https://www.birdsoutsidemywindow.org/2018/06/16/pleated-leaves/
Bilobed leaves- https://www.collinsdictionary.com/dictionary/english/bilobate

If flowers are present identification will be a lot easier- I was going to make a flower key for this article but decided against it. If you need help with identifying an epiphytic orchid feel free to tag me @ludwig_muller
Note that it is possible, at least in theory, for the forest orchid Bonatea speciosa to grow epiphytically. I have never heard of this happening, but if you do find such a specimen it can be easily told apart from other epiphytic orchids by the prominent black "sheath" clasping the base of the stem. This "sheath" is shown clearly here- 2nd pic from left: https://www.inaturalist.org/observations/107758802
For more information, I would recommend Redlist. See below:
http://redlist.sanbi.org/species.php?species=2762-2 Angraecum conchiferum
http://redlist.sanbi.org/species.php?species=2762-4 A. pusillum
http://redlist.sanbi.org/species.php?species=2762-5 A. sacciferum
http://redlist.sanbi.org/species.php?species=2765-3 Calanthe sylvatica
http://redlist.sanbi.org/species.php?species=2815-1 Cyrtorchis arcuata
http://redlist.sanbi.org/species.php?species=2807-6 Liparis remota
http://redlist.sanbi.org/species.php?species=2790-4 Mystacidium capense
http://redlist.sanbi.org/species.php?species=2770-13 Polystachya ottoniana
http://redlist.sanbi.org/species.php?species=2821-1 Tridactyle bicaudata subsp. bicaudata

And finally, here is the info from Orchids of South Africa by Johnson & Bytebier:
Angraecum conchiferum- 8-16 leaves, adjacent, narrowly strap-shaped, unequally bilobed,
30-60 x 4-8mm, stem to 300mm. Often on Yellowwoods (Podocarpus sp, especially P. falcatus).
A. pusillum- 5-10 leaves, grass- like, linear, rounded, thin, in dense terminal cluster on stem,
40-160 x 3-4mm. Old inflorescences persistent.
A. sacciferum- 4-8 leaves, stiff, nearly erect, flat, linear to strap- shaped, obscurely and unevenly bilobed, 20-60 x 3-7mm. Stem to 40mm. Old inflorescences persistent.
Calanthe sylvatica- Leaves pleated, thin, 200-400 x 70-115mm, plant to 70cm.
Cyrtorchis arcuata- Leaves strap- shaped, folded together basally (Author's note: This trait is not very obvious or reliable), unequally bilobed, pale green, 100-160 x 20-30mm. Stem to 400mm.
Mystacidium capense- leaves strap- shaped, unequally bilobed, 40-120 x 10-22mm. Stem to 25mm.
Polystachya ottoniana- 2-3 leaves per pseudobulb/plant, linear to strap- shaped, 20-130 x 4-8mm. Up to 150mm tall.
Tridactyle bicaudata subsp. bicaudata- Leaves arranged in two opposite rows, leathery, linear to strap- shaped, rounded, unequally bilobed, 60-120 x 7-12mm.

Acknowledgements:
I wish to thank Dr Niels Jacobsen for his guidance and mentorship and Dr Brendan Cole for being so supportive of this project.

References:
Liltved, W., Johnson, S., 2012. The Cape Orchids: A Regional Monograph of the Orchids of
the Cape Floristic Region
. Sandstone Publications, Cape Town.
Johnson, S.D., Bytebier, B., 2015. Orchids of South Africa: A Field Guide. Struik, Cape Town
Crouch, N. R., Klopper, R. R., Burrows, J. E., Burrows, S. M., 2011. Ferns of Southern Africa: A comprehensive guide. Random House Struik, South Africa

Ingresado el 20 de abril de 2022 por ludwig_muller ludwig_muller | 4 comentarios | Deja un comentario

14 de abril de 2022

Holothrix IDs in the Southern Cape based on leaves

@sedgesrock @malthinus @justinponder2505 @ren_hoekstra @christiaan_viljoen @milewski @knysna_wildflowers @tonyrebelo

We all know the frustration that comes from not being able to ID an orchid- especially when there is no flower. For when a flower is present, the Orchids of South Africa makes identification easy, but when the flower is absent there is not, as far as I am aware, a book concentrating specifically on orchid leaves. So this article aims to clear up some of the confusion regarding tricky IDs in the genus Holothrix- based on leaf structure, colour, hairiness, size and shape. All the type observations have leaf pics. I have included 11 species and 2 varieties as occuring in this area, namely:

Holothrix brevipetala- type observation https://www.inaturalist.org/observations/37464114
H. burchellii- type observation https://www.inaturalist.org/observations/97908227
H. cernua- type observation https://www.inaturalist.org/observations/99342981
H. exilis- type observation https://www.inaturalist.org/observations/98610067
H. grandiflora- type observation https://www.inaturalist.org/observations/10980768
H. mundii- type observation https://www.inaturalist.org/observations/92901849
H. parviflora- type observation https://www.inaturalist.org/observations/97642970
H. pilosa- type observation https://www.inaturalist.org/observations/95608185
H. schlechteriana- type observation https://www.inaturalist.org/observations/107177600
H. secunda- type observation https://www.inaturalist.org/observations/98290696
H. villosa var. villosa- type observation https://www.inaturalist.org/observations/99341754
H. villosa var. condensata- type observation https://www.inaturalist.org/observations/107879164

Firstly, we need to exclude some other species and families often confused with Holothrix.
According to https://www.inaturalist.org/taxa/119761-Holothrix, we are faced with the genera
Ornithogalum, Massonia, Satyrium, Eriospermum and Platanthera, an orchid genus from the Northern hemisphere.
I will exclude Platanthera from the start, assuming it does not and never will occur naturally in South Africa, let alone the Southern Cape.
In my experience, Eriospermum and Ornithogalum are the two genera that are most often confused with Holothrix.

Eriospermum examples can be seen here:
https://www.inaturalist.org/observations/77237656 Eriospermum dielsianum
https://www.inaturalist.org/observations/41748832 E. pubescens
https://www.inaturalist.org/observations/49986272 E. capense
https://www.inaturalist.org/observations/24740687 E. vermiforme
https://www.inaturalist.org/observations/11110583 E. brevipes

Observations where Holothrix and Eriospermum have been confused:
https://www.inaturalist.org/observations/95013397
https://www.inaturalist.org/observations/29227821

The two Ornithogalums most frequently confused with Holothrix are dubium and hispidum. See links below:
https://www.inaturalist.org/observations/75938927 Ornithogalum dubium
https://www.inaturalist.org/observations/77584041 O. dubium
https://www.inaturalist.org/observations/77870868 O. hispidum
https://www.inaturalist.org/observations/110642149 O. hispidum

Ornithogalum and Holothrix confusion:
https://www.inaturalist.org/observations/99701654
https://www.inaturalist.org/observations/51998115

Massonias are not generally confused with Holothrix, but confusion does arise at times. See below for typical Massonia examples:
https://www.inaturalist.org/observations/72673295 Massonia longipes
https://www.inaturalist.org/observations/89691522 M. depressa
https://www.inaturalist.org/observations/82992734 M. depressa
https://www.inaturalist.org/observations/82824040 M. setulosa

Examples of Holothrix- Massonia confusion:
https://www.inaturalist.org/observations/77043892
https://www.inaturalist.org/observations/32754037

The orchid genus Satyrium can normally be distigiushed from Holothrix by the large consistently glabrous light green leaves. These are typical examples:
https://www.inaturalist.org/observations/97142151 Satyrium membranaceum
https://www.inaturalist.org/observations/94206185 S. muticum
https://www.inaturalist.org/observations/102163407 S. acuminatum
https://www.inaturalist.org/observations/99341756 S. erectum

The inevitable confusion:
https://www.inaturalist.org/observations/87116912
https://www.inaturalist.org/observations/70733950
https://www.inaturalist.org/observations/85309674

One genus which Inat fails to list as a potential candidate for confusion with Holothrix is Bartholina. I include it here due to its close relationship with Holothrix and the fact that thay co-occur throughout this area. Bartholina differs from Holothrix in several ways with its small single leaf and prominent white veins in etheliae's case.
https://www.inaturalist.org/observations/94472308 Bartholina burmanniana
https://www.inaturalist.org/observations/101685854 B. burmanniana
https://www.inaturalist.org/observations/86025656 B. etheliae
https://www.inaturalist.org/observations/65139309 B. etheliae

Right- now that the other genera and families have been excluded we can get down to the nitty-gritty of Holothrix itself. I have made a simple key specially for this article- please note that the key is not completely foolproof and should not be used out of our area. What I mean when I say that the key is not watertight is simply that some populations of Holothrix cernua out of this region lack leaf hair.

Anyway, here it is. I'm afraid that I could not make a key for use with only leaves, and had to bring flower stalks and the flowers themselves into the picture, but I'll try to amend that with a list culled from Orchids of South Africa later on. I've also tried to make it as user-friendly as possible.

    1. Leaves hairy above....... 2.1
      -Leaves hairless above....... 3.1

  • 2.1 Leaves with "scales" or short hooked hairs....... Holothrix cernua
    -Hairs not hooked, lacking "scales" ....... 2.2

  • 2.2 Hairs on flower stalk deflexed - turned sharply downward....... H. brevipetala
    -Hairs on stalk more or less at right angles to the stalk....... 2.3

  • 2.3 Spur- little tail behind flower- less than or equal to 1.9mm long....... H. exilis
    -Spur greater than 1.9mm....... 2.4

  • 2.4 Lip 3-lobed ( divided in three ), central lobe curved upwards....... H. villosa var. condensata
    -Lip 3-lobed, central lobe no different from the others....... H. villosa var. villosa

  • 3.1 Underside of leaf hairy....... Holothrix pilosa
    -Lacking hair underneath....... 3.2

  • 3.2 Tiny hairs along leaf margin, spur straight....... H. mundii
    -Lacking marginal hair, spur slightly to strongly curved....... 3.3

  • 3.3 Bracts present....... 3.4
    -Bracts absent....... 3.6

  • 3.4 More than 7 bracts....... H. grandiflora
    -No. of bracts less than or equal to 7....... 3.5

  • 3.5 Relatively long deflexed hair on flower stalk....... H. burchellii
    -Hair on stalk, if present, pubescent ( like velvet )....... H. schlechteriana

  • 3.6 Lip 5-lobed ( divided in 5 ), lobes more or less rectangular....... H. parviflora
    -Lip 5-lobed, lobes linear, acuminate ( tapering to a point )....... H. secunda

In case there was any confusion or difficulty using the key, here are some useful tips and definitions:
What are bracts? See https://en.wikipedia.org/wiki/Bract and https://www.merriam-webster.com/dictionary/bract
And spurs? Those tiny "tails"? See https://en.wikipedia.org/wiki/Nectar_spur Also in https://www.inaturalist.org/observations/54393258 the spur is the tiny J-shaped curl visible on the lower 3 flowers.
When a leaf is referred to as being hairless above, what should it look like? See the third pic from the left in this observation: https://www.inaturalist.org/observations/31532859
And when a leaf is hairy above? https://www.inaturalist.org/observations/77229011 and https://www.inaturalist.org/observations/100227957 are prime examples of upper surface hairiness.
And what do hairy margins look like? ( article 3.2 ) See https://www.inaturalist.org/observations/92901849
And lip lobes? See the illustration of Orchis italica here: https://en.wikipedia.org/wiki/Labellum_(botany)

Info from the Orchids of South Africa and the Cape Orchids:
Holothrix breviptala- leaf pressed flat, hairy with stout hairs, less than or equal to 12mm in width
H. burchellii- leaf pressed flat against the ground, less than or equal to 60mm broad
H. cernua- leaf pressed flat, covered with short, stiff, hooked hairs above, less than 30mm broad
H. exilis- leaf pressed flat, sparsely hairy above, leaf width uncertain, probably 18mm wide
H. grandiflora- leaf pressed flat, glabrous, less than or equal to 80mm broad
H. mundii- leaf pressed flat, glabrous, short marginal hairs present, less than 21mm wide
H. parviflora- pressed flat or slightly raised, glabrous,less than or equal to 30mm wide
H. pilosa- leaves flat, upper surface glabrous, underside and margins hairy, less than 145mm wide
H. schlechteriana- leaf pressed flat to the ground, glabrous, less than or equal to 100mm wide
H. secunda- leaf pressed flat, glabrous, width uncertain, probably less than 80mm wide
H. villosa- both varieties- leaf pressed flat with a sparse to dense scattering of long hairs on upper surface, less than or equal to 95mm

Further reading:
http://redlist.sanbi.org/species.php?species=2841-2 Holothrix brevipetala
http://redlist.sanbi.org/species.php?species=2841-3 H. burchellii
http://redlist.sanbi.org/species.php?species=2841-4 H. cernua
http://redlist.sanbi.org/species.php?species=2841-9 H. exilis
http://redlist.sanbi.org/species.php?species=2841-12 H. grandiflora DDD
http://redlist.sanbi.org/species.php?species=2841-20 H. mundii
http://redlist.sanbi.org/species.php?species=2841-22 H. parviflora
http://redlist.sanbi.org/species.php?species=2841-24 H. pilosa NT
http://redlist.sanbi.org/species.php?species=2841-27 H. schlechteriana
http://redlist.sanbi.org/species.php?species=2841-29 H. secunda
http://redlist.sanbi.org/species.php?species=2841-32 H. villosa var. condensata
http://redlist.sanbi.org/species.php?species=2841-33 H. villosa var. villosa

Ingresado el 14 de abril de 2022 por ludwig_muller ludwig_muller | 8 comentarios | Deja un comentario

04 de marzo de 2022

Holothrix in the George area

@tonyrebelo @jeremygilmore @justinponder2505 @ren_hoekstra @malthinus @sedgesrock @milewski @christiaan_viljoen

Today I have a challenge- a question that needs answering. Here it is:

Many people have noted the odd forms of Holothrix in the Outeniquas/George area, in particular H. brevipetala, H. exilis and H. villosa var. condensata. They grow long, slender, reed-like peduncles/stalks and the flowers are well spaced on the inflorescence.

As examples-
Villosa var. condensata:
https://www.inaturalist.org/observations/107879164
https://www.inaturalist.org/observations/102705460
https://www.inaturalist.org/observations/10825517
A more robust form: https://www.inaturalist.org/observations/107879163

Brevipetala:
https://www.inaturalist.org/observations/11188064
https://www.inaturalist.org/observations/11188047
https://www.inaturalist.org/observations/21943295
https://www.inaturalist.org/observations/104707154

Exilis- records very sparse:
https://www.inaturalist.org/observations/11224432

Now- the usual forms:
Villosa var. condensata:
https://www.inaturalist.org/observations/104722684
https://www.inaturalist.org/observations/104190741
https://www.inaturalist.org/observations/11171000

Brevipetala:
https://www.inaturalist.org/observations/103585361
https://www.inaturalist.org/observations/59859659
https://www.inaturalist.org/observations/80237415

Exilis:
https://www.inaturalist.org/observations/11233801
https://www.inaturalist.org/observations/17320561

The obvious question is "Why do they grow like this here and only here?"
In brevipetala the tall form seems to extend along the Cape Fold Mountains, but the reed-like form of exilis is rare and sporadic, and villosa var. condensata is even more patchy, though locally common in spots.
We should attempt to answer this question by asking "What is different about the Outeniquas?"
In other words....
Do the pollinators fly higher?
Is the weather more ideal for such growth?
Is there less wind?
Etc...

Any suggestions?

Ingresado el 04 de marzo de 2022 por ludwig_muller ludwig_muller | 5 comentarios | Deja un comentario

14 de febrero de 2022

Confusion surrounding the coastal Habenaria, Bonatea and Liparis IDs: separating them by leaf structure

@tonyrebelo @milewski @markheystek @justinponder2505 @ren_hoekstra @malthinus @jeremygilmore @seroff55 @erickmunro @christiaan_viljoen @dhoare @sedgesrock

Hi guys,
I have not written a scientific article before- this is my first attempt, so please bear with me and any mistakes I might have made. If you have any helpful comments or constructive criticism please send me a message on inat or mail me at ludwigxem@gmail.com .

I saw the need for an article addressing the considerable confusion surrounding Habenaria, Liparis and Bonatea IDs on inat- see https://www.inaturalist.org/observations/105954597 , https://www.inaturalist.org/observations/76911000 and https://www.inaturalist.org/observations/68596478 .

I will be focusing on 3 species- Liparis remota, Bonatea speciosa and Habenaria arenaria. Other species in these genera that might/also occur here are Habenaria laevigata, Habenaria falcicornis, Habenaria lithophila and Liparis capensis- based on records from The Cape Orchids. They also list a few other Habenarias that I think are too unlikely to occur here so have not included them.
Liparis capensis is excluded because of it's limited range in our area- see https://www.inaturalist.org/observations?place_id=126458&subview=map&taxon_id=589246 - and also because I have no personal experience with this species. I lack notes, photos, fieldwork etc.
Habenaria laevigata has been recorded from Ruitersbos- not coastal
H.lithophila occurs along the mountains, not the coast.
H. falcicornis was reported from Keurboomstrand and might well be worth searching for, but I lack the necessary photos and fieldwork on this species.

I will start by selecting my "type" observations- observations that, beyond doubt, are identified correctly.
Liparis remota:
https://www.inaturalist.org/observations/105900057
https://www.inaturalist.org/observations/77615173
https://www.inaturalist.org/observations/69093840
Habenaria arenaria:
https://www.inaturalist.org/observations/102165332
https://www.inaturalist.org/observations/77233833
https://www.inaturalist.org/observations/40175587
Bonatea speciosa:
https://www.inaturalist.org/observations/105953127
https://www.inaturalist.org/observations/105953111
https://www.inaturalist.org/observations/102870148
https://www.inaturalist.org/observations/100070252

Flowering time is also important:
Bonatea flowers from June to December, in the Garden Route mostly from September to November
Habenaria flowers from (Mar) April to July (Sep)
Liparis flowers from November to March, but in our area mostly January and Febraury

When flowering the species can easily be told apart. Unfortunately the young Bonateas most frequently confused with Habenaria have not yet reached flowering age. I was helped enormously by a recent visit to Nature's Valley, where I found all three species growing side by side in coastal forest on leaf litter and sand. Here are the main differences:

Liparis:
Prominent grooves/stripes running the length of the leaf.
Lack of spots on the leaf.
Most plants have two leaves, rarely three.
The leaves are normally parallel to the ground, at some height off above it. The leaves are almost never pressed close to the ground.
The tip is also, in most cases, reflexed/recurved underneath the leaf, presenting a blunt apex.
This is the smallest orchid of the three in this article, although confusion might arise with a smaller Habenaria vs a large Liparis.
Underside of leaf is a light green.

Habenaria:
Single groove/stripe running up the center of the leaf.
Approximately 60-75% of most large Habenaria populations in our area is composed of plants with white spots/ speckles on the leaves. The remaining minority has plain green leaves. This creates much confusion with the other two, especially in the coastal habitat where all grow together.
Plants normally have one, often two and rarely three leaves.
The leaf tips in a two leaved plant normally point in opposite directions.
The leaves tend to be either flattened to the ground or raised to an angle of about 30 degrees. Exceptions occur in low light conditions, where the leaves reach higher to about 40 degrees.
The leaf apex is mostly sharp and pointed.
This is the 2nd largest of the three orchids, especially when flowering.
Underside of leaf pale whitish- green to white.

Bonatea:
In young plants a single groove runs the length of the leaf, from base to apex.
At the base of a stem there is almost always ( I have never found it missing) a black sheath encasing the area below the leaves. A very reliable method of identification.
In most plants except the very young there are more than 2 leaves. Also, these leaves radiate outwards in all directions and the plant is normally at some height off the ground.
The leaves of Bonatea speciosa are almost never pressed flat against the ground. Even in young plants the leaves are raised, the tip being higher off the ground than the base.
The leaf is rounded in older plants and even in younger plants the tip is not sharp.
This is the largest of the three species, reaching roughly 50cm in height when fully grown.
Underside of leaf whitish.

Hopefully this article will help clear up some of the confusion regarding these species on inat. Identifying orchids from leaves only is difficult at the best of times- example https://www.inaturalist.org/observations/90529635 ( I thought it was coriifolium due to the raised leaves but a visit to the site when the plants were in flower showed otherwise).
If anyone needs help identifying orchids please feel free to tag me. I have enjoyed compiling this article and hopefully you've enjoyed reading it ;)

Ingresado el 14 de febrero de 2022 por ludwig_muller ludwig_muller | 2 comentarios | Deja un comentario

21 de mayo de 2021

https://www.inaturalist.org/observations/11038840

Cape Warthog - an overlooked pig

The Cape Warthog used to occur in the EC and adj. KZN. It is unsure how far west it extended, perhaps over much of the old Cape s of the Orange River.
It probably went extinct in the 1870s in the EC.
.
Rediscovery of the Cape warthog Phacochoerus aethiopicus: a review.
P Grubb & J-P d’Huart 2010
Journal of East African Natural History: 99:

Abstract

Warthogs without incisors were described from the Cape of Good Hope as Phacochoerus aethiopicus and warthogs possessing incisors were first found in Senegal and later named Phacochoerus africanus. During the second half of the 18th century and the whole of the 19th century, the majority of workers recognised these two taxa as distinct. Twentieth century palaeontologists working in Africa also recognised the two species of warthogs in the Pleistocene and Holocene fossil records and were aware of the differences between the two Recent species. But in the same period, most zoologists considered all warthogs to belong to a single polytypic species. Re-examination of the literature and inspection of recent material confirm distinctive differences corresponding with geographic distribution of two species of warthogs: the widespread Common Warthog Phacochoerus africanus and the Cape Warthog P. aethiopicus. Whereas the Cape Warthog, P. aethiopicus aethiopicus, became extinct in South Africa in the 1870s, a geographically isolated subspecies, P. aethiopicus delamerei, survives in Kenya, Ethiopia and Somalia. This discontinuous distribution has been noted in the literature, as are the criteria which distinguish P. aethiopicus from P. africanus.
.
Keywords: Phacochoerus aethiopicus, warthog systematics, geographical isolation, morphology.

(http://www.ajol.info/index.php/jeanh/article/view/66018)
.

.
More reading:
https://sites.google.com/site/wildpigspecialistgroup/home/Phacochoerus-aethiopicus
https://en.wikipedia.org/wiki/Cape_warthog
http://www.mhs.ox.ac.uk/naturalhistories/Order.html
http://www.africahunting.com/threads/the-common-warthog-and-the-desert-warthog.15224/

Ingresado el 21 de mayo de 2021 por ludwig_muller ludwig_muller | 3 comentarios | Deja un comentario

19 de abril de 2021

Accipiter identification

colin25 suggested an ID ID Withdrawn
6d
Micronisus gabar
Gabar Goshawk
Micronisus gabar
krista_oswald suggested an ID ID Withdrawn
6d
Micronisus gabar
Gabar Goshawk
Micronisus gabar
christiaan_viljoen commented
1d

Just for interest sake, why are you saying that it is not a Black Sparrowhawk?
christiaan_viljoen commented
1d

The bird looks quite bulky, but it's very different for me to judge the size. The photographer will have to tell us if it was the size of a Rock Kestrel or the size of a Forest Buzzard...
christiaan_viljoen commented
1d

I suppose it could also be a melanistic African Goshawk. But that would be a very rare sighting indeed.
christiaan_viljoen commented
1d

I am just mentioning other options because the habitat is completely wrong for Gabar Goshawk...
colin25 commented
1d

Size hard to judge as it was soaring. Probably more kestrel size though. Other birders have seen this bird more or less at the same time and also think Gabar, despite habitat issue.
christiaan_viljoen commented
1d

Someone needs to call it to see it if will respond and even better, call back, their calls are very distinctive.

It's very highly unlikely to be a Gabar Goshawk, but if so, it will be an awesome observation for George.
christiaan_viljoen commented
1d

@julianparsons, @justinponder2505, @markheystek, @ludwig_muller
markheystek commented
1d

Thanks for tagging me. This Accipiter has got a yellow cere and legs but Gabar Goshawks have red ceres and legs don't they? Going according to that I'm sure this is one of the many Black Spars that hang around the Witfontein forest. Size would be the best key indeed!
krista_oswald commented
1d

I had gone with melanistic Gabar (which I've seen) because of the full black throat (which I had never seen on Black Sparr). I did now do some googling of images and it seems there is a lot of variation in the underside, so I withdrew my ID. The ceres is definitely a good pointer away from Gabar.
markheystek commented
1d

Ja, I thought about the white throat-patch too... Almost all the melanistic Black Spars I've seen here have had white on the throat, and in fact I only know of one individual in the area that is not melanistic, so there's definitely a higher chance of seeing a melanistic B Spar in this area! Would be super cool to have a Gabar though...
christiaan_viljoen commented
19h

So what about the possibility of a Melanistic African Goshawk???
krista_oswald commented
16h

... @christiaan_viljoen I have no good excuse or reasoning. Again, I can just say that because I've seen melanistic Gabar that's where my mind went. A really bad assumption and I should have refrained from an ID. Although, the ceres/feet would also point away from AfGos.
christiaan_viljoen commented
6h

I am just worried about the size of the bird. A Black Sparrowhawk is a really large bird. I saw one this morning, same size as the Pied Crow that chasing it, if not larger. In fact the tables soon turned and then it was chasing the crow. If the observer says this bird was much smaller then we might have to consider African Goshawk.

The eye and cere colour also matches African Goshawk. The only problem I have is the darkish eye. But the melanin might also affect the eye colour?
christiaan_viljoen commented
6h

@trevor102, @johnnybirder, @rion_c, @ianrijsdijk
christiaan_viljoen commented
6h

Have a look a the following observation of what I think is quite clearly a melanistic African Goshawk. Note the yellow eye...

https://www.inaturalist.org/observations/47861387

Based on that observation I would say that this is certainly a fully melanistic Black Sparrowhawk.
christiaan_viljoen suggested an ID* Leading
6h
Accipiter melanoleucus
Black Sparrowhawk
Accipiter melanoleucus

  • christiaan_viljoen disagrees this is Gabar Goshawk Micronisus gabar
    colin25 commented
    6h

I do have a "problem" with colours, fail those dreaded pale dots tests where you are supposed to see numbers, but to my dubious eye the legs are more red than yellow. Just my eye leading me astray?
christiaan_viljoen commented
6h

Cere is yellow and feet are orange-yellow. Not orange-red and certainly not red. In fact, I recently saw Gabar Goshawk in Mokala NP and their legs are almost pinkish-red.

Also consider that a melanistic bird might have slightly darker legs. I noticed that the legs of a melanistic Gabar Goshawk was a deeper red-orange, compared to its normal looking mate which had pinkish-red legs and feed. I will send provide a link to my observations of the Gabars at Mokala below.
christiaan_viljoen commented
6h

Melanistic Gabar Goshawk:

https://www.inaturalist.org/observations/74493587

and is mate:

https://www.inaturalist.org/observations/74493638

Note the colour of the legs and feet.
ianrijsdijk commented
3h

My first thought was Black Spar, especially with the wing profile in the second shot, and keeping mind that the males are somewhat smaller than the females. The lack of a white throat patch did worry me, though I have seen a very dark bird in the Tokai area that, as I remember it, has no white patch. Ulrich Oberprieler's book has an all black bird. I'm not as familiar with Gabar, especially in its melanistic form.

https://www.inaturalist.org/observations/73832307#activity_comment_9f1af140-ba60-496d-86c2-d0b932ff4f0d

Ingresado el 19 de abril de 2021 por ludwig_muller ludwig_muller | 0 comentarios | Deja un comentario

15 de marzo de 2021

Indigenous fish taxonomy

david_taylor suggested an ID
1y
Pseudobarbus
Redfins
Genus Pseudobarbus
david_taylor commented
1y

@darragh132 Not P. burchelli? Looks like the breede system and I don't think its P. skeltoni
darragh132 commented
1y

@david_taylor According to the taxonomists at SAIAB, P. burchelli (the Barrydale Redfin) is a unique lineage restricted to the Tradouw River catchment north of Swellendam. All Pseudobarbus burchelli in the rest of the system belong to a separate lineage, which is currently being referred to as P. sp nov "burchelli breede" but has no taxonomic authority until a description is published. The same situation is true for the "Cape zebra" Galaxias zebratus, which apparently should only be used to refer to one of two cryptic species restricted to the south-western Cape (there are 9 others across the Cape Fold Ecoregion). @tonyrebelo has already flagged this issue with the iNaturalist taxonomy team, so we will see if these "unique lineages" of redfins can get temporary species status for the purposes of observation reporting on this platform at least, while we wait for the taxonomists to clear their substantial backlog of undescribed lineages
david_taylor commented
1y

@darragh132 thanks for the clarification. I will follow this with interest. Is it Albert who is sorting this out?
darragh132 commented
1y

@david_taylor Yes Albert is slowly working through the Pseudobarbus, Galaxias and some Enteromius groups. I believe he is close to publishing a revision of Enteromius anoplus in the Western Cape, to give the ones found in the Cederberg new species status (he presented his student's work on this at a freshwater conference last year). The Breede Catchment galaxiids and redfins are somewhere further down the queue. There is a recent review paper in Aquatic Conservation that gives an overview of the taxonomic backlog (DOI: 10.1002/aqc.2730)
tonyrebelo commented
1y

Austroglanis barnardi (Skelton, 1981) EN Endemic to Olifants River system, specifically three tributary streams
Austroglanis gilli (Barnard, 1943) VU Endemic to Olifants River system

Enteromius anoplus (Weber, 1897) LC Widely distributed throughout South Africa
Enteromius sp. “pallidus south” LC Widespread across the eastern CFR from the Krom River in the west to the Great Fish River system in the east

Galaxias zebratus Castelnau, 1861 DD Type locality uncertain and requires revision

Galaxias sp. “zebratus Breede” NA Hex, Bothaspruit and mainstem Breede River system
Galaxias sp. “zebratus Goukou” NA Goukou River system
Galaxias sp. “zebratus Heuningnes” NA Heuningnes and Ratel River systems
Galaxias sp. “zebratus Klein” NA Klein, Uilkraals and Ratel River systems
Galaxias sp. “zebratus Mollis” NA Onrus River system and Leeu River, Berg River system
Galaxias sp. “zebratus nebula” NA Widespread across the CFR from the Olifants River system in the west to the Bitou River system in the east
Galaxias sp. “zebratus Rectognathus” NA Amandel and Du Toit Rivers, Riviersonderend sub‐catchment, Breede River system
Galaxias sp. “zebratus Riviersonderend” NA Tributaries of the Riviersonderend River and in the Keurbooms River, Breede River system. Also occurs in the Palmiet River system
Galaxias sp. “zebratus Slender” NA Uilkraals River system

Labeo seeberi Gilchrist & Thompson, 1911 EN Endemic to Olifants River system, specifically (currently) the Doring River main stream
Labeo umbratus (A. Smith, 1841) LC East coast rivers from Gouritz to Bushmans rivers and the Orange/Vaal River system

Labeobarbus seeberi (Gilchrist and Thompson, 1913) CVU Endemic to Olifants River system

Pseudobarbus afer (Peters, 1864) EN Headwater tributaries of the Baakens, Swartkops and Sundays River systems

  1. Pseudobarbus sp. “afer Forest” NT East coast from Klein Brak to Tsitsikamma rivers
  2. Pseudobarbus sp. “afer Gamtoos” EN Headwater tributaries of the Gamtoos River system
  3. Pseudobarbus sp. “afer Krom” CR Headwater tributaries of the Krom River system
    Pseudobarbus asper (Boulenger, 1911) EN Mainstream reaches of the Gamtoos and Gourits River systems
    Pseudobarbus burchelli Smith, 1841 CR Tradouw River, Breede River system

  4. Pseudobarbus sp. “burchelli Breede” NT Headwater tributaries of the Breede, Duiwenhoks and Goukou River systems
  5. Pseudobarbus sp. “burchelli Heuningnes” CR Heuningnes River system
    Pseudobarbus burgi (Boulenger, 1911) EN Endemic to the Berg River system
    Pseudobarbus phlegethon (Barnard, 1938) EN Occurs in the Oudste, Thee, Noordhoeks, Boskloof and Rondegat tributaries of the Olifants River system

  6. Pseudobarbus sp. “phlegethon Doring” CR Breekrans and Driehoeks tributaries of the Doring River, Olifants River system
    Pseudobarbus skeltoni Chakona & Swartz, 2013 NA Limited to two localities within the Breede River system (upper Riviersonderend and Krom rivers)
    Pseudobarbus tenuis (Barnard, 1938) NT Headwater tributaries of the Gouritz River system

  7. Pseudobarbus sp. “tenuis Keurbooms” EN Headwater tributaries of the Keurbooms and Bitou River systems
    Pseudobarbus verloreni Chakona, Swartz & Skelton, 20143 EN Verlorenvlei River system
    ‘Pseudobarbus’ capensis (Smith, 1841) EN Endemic to the Berg and Breede River systems
    ‘Pseudobarbus’ calidus (Barnard, 1938) V Endemic to the Olifants River system
    ‘Pseudobarbus’ erubescens (Skelton, 1974) CR Endemic to the Olifants River system, specifically the Twee River and its tributaries
    ‘Pseudobarbus’ serra (Peters, 1864) EN Endemic to the Olifants River system

Sandelia capensis (Cuvier, 1831) DD Type locality uncertain and requires revision

  1. Sandelia sp. “capensis Breede” NA Tributaries of the Breede, Duiwenhoks and Goukou River systems
  2. Sandelia sp. “capensis Agulhas” NA Heuningnes, Haelkraal and Klein River systems
  3. Sandelia sp. “capensis Klein” NA Klein River system
  4. Sandelia sp. “capensis Koekedou” NA Titus and Koekedou, tributaries of the Breede River system
  5. Sandelia sp. “capensis Riviersonderend” NA Tributaries of the Riviersonderend River, Breede River system
    ludwig_muller commented
    1y

Hi @darragh132 Your info on Enteromius anoplus is most interesting as l have recently discovered what may be a new Enteromius in the Free state. Is the species being split up?
ludwig_muller suggested an ID
1y
Pseudobarbus
Redfins
Genus Pseudobarbus
darragh132 commented
1y

@ludwig_muller Yes the western populations of Enteromius anoplus (including those occurring in Eastern Cape, Northern Cape, Western Cape and Free State) are currently undergoing taxonomic revision at SAIAB, led by a PhD student that is close to submitting. I expect to see the new species descriptions published later this year or in early 2021.

Ingresado el 15 de marzo de 2021 por ludwig_muller ludwig_muller | 0 comentarios | Deja un comentario

24 de febrero de 2021

Locations

While we are on the point of obscuring locations for animals, and as Tony have mentioned Rhinos, I want to point out something that worries me. I have for this reason removed all my Rhino observations from iNaturalist.

Black Rhino are critically endangered, to the point that National Parks that have these animals do not even put them on their Mammal checklists. However, if you enter Black Rhino on the Explore option and search for them and look at the wider picture of things, I do think it is fairly easy to determine, using iNaturalist, which National Parks have Black Rhino and which don't. If I add all my Black Rhino sightings then I believe it would be even more obvious, by looking at the general area where they have been obscured, to work out from which Park they are and that might lead to poachers then targeting a Park which few people even know have Rhino... Please correct me if I am wrong. But go and see for yourself. All the Black Rhino strongholds are clearly visible on iNaturalist and I don't want them to become more so if I add my observations. I was even contemplating adding them with locations showing them to be anywhere within South Africa but that would defeat the purpose of the data. However, I do think that if iNaturalist do increase the level of obscurity given to an obscured observation, especially critically endangered species, maybe from 22km to 222km then that would help to confuse poachers completely as to where the Rhino could be. Then I would have comfort in adding all my Rhino observations.
christiaan_viljoen commented
3d

@kueda
tonyrebelo commented
3d

Although SANParks have removed rhinos from some parks for some sites, they are still available in all the literature and in archived versions of the sites.
Hiding data that is already out there, or that is obvious, achieves nothing other than a false sense of security for those overly worried, while leaving the animals (and plants!!) just as vulnerable as before.
Meanwhile social media continue to leak locations, available to anyone with even rudimentory data mining skills.
We have to balance risk with safety. We dont want to discover that Rhinos are extinct at Mountain Zebra National Park, because everyone was too scared to record them.
None of this is helped when park rangers and officials are in the pay of the criminal syndicates!
Furthermore, what is the point of hiding your data, when any visitor wanting to earn a few extra dollars, can report sighting directly to the poachers, and indeed poacher informants can visit the parks and map dung and sightings, when some visitors are too scared to report their sightings. It means that conservation authorities and scientists have less access to data, but criminals have more (and esp. so when there are a few corrupt officials).
Sometimes I wonder if the criminal syndicates are not behind the move to obscure and remove data, so that their activities are not noticed by the public. Especially with regard to succulent and bulb trade, where the fewer people are aware of localities, the longer the time to detection when these are poached.
christiaan_viljoen commented
3d

Plants are another matter altogether, because they cannot even run away, and there GPS location will be dead accurate. But the obscure location option works will for plants such. Especially plants that are highly sort after on the collector's (black) market and yet not classified as endangered (so thus not automatically obscured). This, for example, incudes many species Haworthiads. I usually remember to obscure any plant species that I reckon might be appealing to careless collectors.

But Rhino are another matter. You will never get a pin location on a rhino as you would for a plant, but a bunch of pins in the same area would indicate a healthy breeding population which could then be targeted. I don't think that it is necessary to monitor rhino populations using platforms such as iNaturalist. Whereas iNaturalist is ideal for getting good information on populations insects and other small creatures; populations of large mammal species, especially those that are endangered are rigorously monitored by conservationists wherever these animals occur. That is way I suggest that we enlarge, by ten fold, the level of obscurity given to endangered mammal species. It should not be possible to determine where (in which Parks and private game reserves) these animals occur using iNaturalist.
michael2838 commented
3d

@christiaan_viljoen , do poachers often use inaturalist? I normally obscure my locations to a degree since @ludwig_muller told me about this. Since it is not always big game that is poached but often other things to.
tonyrebelo commented
3d

"It should not be possible to determine where (in which Parks and private game reserves) these animals occur"
It is a legal requirement that large mammals need to be fenced with electric and strong fencing. There are only so many places that rhinos are allowed. You can count them on your hands and feet. How will obscuring help? For instance current obscuring shows Mokala as two squares and rhinos are in both. And Addo main shows similarly as two squares. If obscuration where 100 times larger, it would still be 100% apparent that these are from Mokala and Addo!
tonyrebelo commented
3d

" do poachers often use inaturalist? "
poachers are sophisticated: not the grunts who pull the triggers, but the organizers. They use drones, facebook, online literature, auction adverts and everything they can get their hands on. And iNaturalist and other sites. And I will wager a crate of Whiskey, that they have access to SANParks internal files, and monitor ranger radios.

Obscuring Haworthias is probably a bit meaningless, because their are countless popular magazines, websites and blogs for this genus, often with localities in excruiting detail. Many of the species are in common trade, and available worldwide from growers.

Fudging data ("normally obscure my locations to a degree") may result in your "known" population being declared extinct, at least until scientists, conservationists and managers discover that your data are unreliable and thus useless for conservation. Given the issues that might arise from fudging localities, posting incorrect localities (even if only to a degree) is simply unethical. Rather dont bother posting them.

Ingresado el 24 de febrero de 2021 por ludwig_muller ludwig_muller | 0 comentarios | Deja un comentario