20 de febrero de 2024

Wingnuts

One of my favorite plant common names is wingnut cryptantha, Cryptantha pterocarya. Arizona Flora treated them as two varieties separated by the number of winged nutlets - four winged nutlets => var. cycloptera vs three winged and one not winged => var. pterocarya. They have since been treated as species and Jepson has a key - see couplet 29. Without nutlets it appears plant color is a good hint - yellow-green for C. cycloptera, gray-green for C. pterocarya. In my experience the calyx lobes are a good spot to check for color. Further, pedicel length can help, longer in C. cycloptera.

Publicado el febrero 20, 2024 06:49 TARDE por stevejones stevejones | 2 comentarios | Deja un comentario

17 de febrero de 2024

Boxing glove cholla around the world

@gitanomad posted a comment on his observation here of Cylindropuntia fulgida var. mamillata curious as to why var. mamillata has been observed worldwide (see map), odd for a variety of a New World species. Spot-checking the observations from Africa and Australia, they all differ quite a bit from what is locally identified as that variety (key to varieties here). The stems are thicker, the tubercles denser and the stems often fasciate, sometimes cresting (a form of fasciation).
I don't know its provenance, but it appears someone found a fasciating var. mamillata, took joints or cuttings and started cultivating it, marketing it as "boxing glove cactus".
Cuttings made their way to Australia, southern Africa and Iberia where they escaped cultivation and became a bit of a pest. There are articles online on biological control using cochineal insects.
There are some variations in the plants found abroad; some seem to have given up fasciation but still carry the characters above - thick stems and dense tubercles.

Publicado el febrero 17, 2024 02:58 TARDE por stevejones stevejones | 0 comentarios | Deja un comentario

09 de febrero de 2024

Lycium flowers

Lycium exsertum is flowering again locally, giving an opportunity to observe pin and thrum heteromorphy. The same condition can also be seen in L. fremontii flowers.

Publicado el febrero 9, 2024 03:36 TARDE por stevejones stevejones | 4 comentarios | Deja un comentario

28 de enero de 2024

Fiddlenecks

There are two taxa in Arizona, Amsinckia menziesii intermedia and Amsinckia tessellata. These are difficult to separate from one another at a glance, but floral characters are useful - the calyx specifically. In the more common and widespread Amsinckia menziesii intermedia the five calyx lobes are all of equal size and separate from one another. The calyx of the less common Amsinckia tessellata is zygomorphic and usually one pair of the lobes will be partially fused along the margin resulting in a notched lobe.
A. tessellata is generally less common and seems to prefer a more moist habitat. Its leaves are also a bit wider as a rule. The two species can be found together in a population.

Publicado el enero 28, 2024 04:07 TARDE por stevejones stevejones | 1 comentario | Deja un comentario

12 de enero de 2024

Eight years on iNaturalist

I overheard @mtluczek in conversation with someone else utter the word "iNaturalist" eight years ago today during a break in a meeting at the old McDowell Sonoran Conservancy office (two office moves ago!). I had no idea what it was, but searched that evening and have been banging on this keyboard ever since.
In an inadvertent celebration (forgot the anniversary until a few minutes ago) I made a pile of observations in preparation for a botany hike I'm leading on Saturday (13th) in the preserve, beginning at Brown's Ranch. (Late notice, but join us if you can). The observation pile is thick with creosote bush galls, including a couple (here and here) that I find intriguing, or just can't make out as a known. Curious about this little booger too.

Publicado el enero 12, 2024 09:21 TARDE por stevejones stevejones | 84 observaciones | 0 comentarios | Deja un comentario

26 de junio de 2023

Rackensack Canyon project

One of my favorite nearby sites on the Tonto NF is Rackensack Canyon. The area is in the transition zone between Arizona upland and interior chaparral biotic communities. This is reflected in the main canyon, with interior chaparral dominating north-facing slopes and Arizona upland on the south-facing slopes. In addition the wash running through the canyon hosts riparian vegetation, including cottonwood, willow, ash, sycamore and net-leaf hackberry. The wash runs WNW to ESE, merging with Camp Creek just below the Cave Creek Road (FS 24) crossing.
I created a collection project for the area using a rough map of the canyon's watershed, cheating a bit on the southern boundary to take in parts of a trail along that boundary.
Rackensack Canyon is a good area for birders and butterfly enthusiasts. I'm not sure about organized bird hikes, but the Central Arizona Butterfly Association (CAzBA) holds occasional field trips in the area.
It's also a good area to hunt for galls. Galls have been observed on numerous species including scrub oak, Arizona juniper, net-leaf hackberry, cottonwood, burrobush, catclaw acacia, desert broom, tarragon, even a euphorb in section Anisophyllum.

Publicado el junio 26, 2023 06:08 TARDE por stevejones stevejones | 7 comentarios | Deja un comentario

13 de marzo de 2023

Granite Mountain wildflower hike

I led a group of McDowell Sonoran Conservancy stewards on a wildflower hike this morning and promised to make these observations from my Friday pre-hike accessible. Great weather, great wildflower show, great group of people.

Publicado el marzo 13, 2023 02:14 MAÑANA por stevejones stevejones | 61 observaciones | 2 comentarios | Deja un comentario

18 de octubre de 2022

e-polycarpa-tubular-gall

In 2012 I first ran across some banana-shaped objects growing on Euphorbia polycarpa plants:

I vouchered the plant material and dissected some of the objects finding only tiny orange larvae which I could not identify. I have occasionally seen the galls since, but this year they have been produced in great numbers, with thousands of them felicitously placed within a few feet of my back porch. Spot-checks in other locations and another observation suggest this has been a particularly good year for the insects involved.

Euphorbia polycarpa is a member of the Euphorbiaceae. The floral structure of euphorbs is unique to the family. A cuplike involucre holds a single stalked female flower at its center, surrounded by one to dozens of male flowers. Male flowers are reduced to just a stalk with paired anthers at the ends. This arrangement is called a cyathium:

The galls are induced in the cyathium of the plant by the act of the galling insect laying its egg. The cyathium itself grows abnormally; glands and appendages normally produced on the rim of the cyathium can be seen at the apex of some galls. The walls of the gall encapsulate the egg, larva, and pupa. The distal end of the gall is open.

Thus began a hunt for the inducer. In near-daily safaris among a dozen or twenty galls at a time, I found almost nothing beyond those familiar orange larvae. The larvae were usually single, but there were multiples in a few, as many as four in a single gall. The larvae were all identical, at least to my untrained eye. Along with near-daily harvests, I placed some material with galls in petri dishes hoping for adults to emerge. Eventually some pupae turned up (images are linked to the observations):

At least two adults were found firmly ensconced in galls, one alive and one not:

All four had the head to the distal end of the gall. Note the ovipositors on the dead adult and pupae. Given the length of the ovipositors, this taxon could be a parasitoid - a parasite on a parasite. With the open end of the gall, they would not even need to perforate the gall wall.

The pupa at right above produced this adult:

All adults are similar, but not identical. Body length of all is similar, just above 2 mm. Some variations:


Female, dorsal view


Male [?] with feathery antennae

The above were found in the galls or resemble those that were. Whether they represent more than one taxon I don't know. I've been sticking with Chalcidoidea, and even that may be wrong with some of them; I'm out of my depth.

Some other wasp or wasp-like insects turned up in the petri dishes. This small wasp is very active and difficult to photograph:

It is the next most numerous wasp. Body is about 1 mm long. Began appearing later than the others, and seems to be thriving in the dishes.
ETA: This appears to be a whitefly parasitoid in the genus Eretmocerus; makes sense since whiteflies are also very common on the E. polycarpa plants. Information at the link (click on photo above).

Beyond those a couple of other wasp-like critters made brief appearances, one each:

Colorful things; possibly the same taxon. Both had bodies of about 1 mm long. Deceased at left, alive at right.

I found galls similar to the Euphorbia polycarpa galls on Euphorbia melanadenia, nearly identical except for the hairs on the outer surface of the galls. The hairs are consistent with that species' usual indument:

There are other images of similar galls on related taxa here and I know there's at least one more out there - will add if found.

I've accumulated quite a pile of adult corpses - couple of dozen so far - if anyone is interested and able to attempt to further ID these critters. There are also links to other observations I made in the hunt here, compiled by the ever-helpful Nathan Taylor, creator of this relevant project.

Bottom line: I have no idea which, if any, of these wasps are inducing the galls.

Publicado el octubre 18, 2022 02:36 TARDE por stevejones stevejones | 5 comentarios | Deja un comentario

12 de septiembre de 2022

Euphorbia polycarpa tubular galls

This gall is one I've seen before on Euphorbia polycarpa in the area, but this year there are literally thousands of the things densely covering many individual plants, many of them within handy reach just off my porch. I've been trying to raise the galls with some success, though I'm not sure I've capture the responsible organism. Larvae are all similar and are included in the first observation below; there is also a pupa, bearing some similarity with the chacidoid wasp. First adults to appear were the parasitoid chalcidoid wasp linked below. Next was the smaller four-winged insect also below. I'm at a loss to ID that one even to order. The individual photographed has some coordination issues. Photos aren't great, but equipment is limited and depth of field suffers.
I also found similar galls on Euphorbia melanadenia in a branch of Rackensack Canyon (third observation).

Publicado el septiembre 12, 2022 11:57 TARDE por stevejones stevejones | 5 observaciones | 1 comentario | Deja un comentario

15 de febrero de 2022

Pin and thrum heteromorphy in Lycium exsertum

Some time ago @emaking introduced me to pin and thrum floral heteromorphy, in which either male or female flower parts in normally perfect flowers are alternately suppressed. Lycium exsertum and its cousin L. fremontii exhibit heterostyly; some of them are functionally dioecious. All flowers of an individual shrub are either:
1) Perfect - male and female parts well-developed
2) Pin flowers with short filaments, reduced anthers and a normal pistil producing functionally female flowers
3) Thrum flowers with short pistil length and anthers large and well-exserted resulting in functionally male flowers

I ran a short survey of the L. exsertum plants on my property, 33 plants, all in flower. Of those, 7 have perfect flowers, 12 have thrum flowers and 13 have pin flowers. Pin flower corollas were generally smaller than perfect and thrum flowers, both shorter and narrower. In addition there was one plant expressing poor development of both male and female parts, representing a fourth condition to add to the list above.

Publicado el febrero 15, 2022 10:06 TARDE por stevejones stevejones | 1 comentario | Deja un comentario