22 de julio de 2018

Field and fen at Franklin Parker

Having been blessed with an excess of energy at the beginning of the summer, I went out in the field again on June 16 on a trip organized by the Mt Cuba Center, and led by Emily Tinalli and Renee Kemmerer, to see some typical New Jersey Pine Barrens flora at the Franklin Parker Preserve.

We started off outside the preserve, examining a roadside patch of candyroot (orange milkwort). A wet ditch nearby held a variety of other interesting plants, including bog clubmoss and bushy bluestem. Entering the preserve, we followed a sand road across the old CNJ Southern Division, picking up typical dry-habitat species like bearberry, pine barren sandwort, and goat's rue. Thanks to directions (and transport) from Mark Szutarski, we got to examine a field nearby which held a spectacular specimen of clasping milkweed.

A wetland below one of the former cranberry bogs held a nice example of Sparganium americanum (bur-reed), with its distinctive infructescences. Our path led us through typical pitch pine-scrub oak forest, with a varied and mostly ericaceous understory, to a fen on the branch that drains the eastern portion of the old bogs into the West Branch of the Wading. A few rose pogonias were still blooming, and the bladderworts are in flower. Encouraged to explore the fen, we cautiously brachiated from white-cedar to white-cedar, finding Sabatia difformis blooming and Lophiola aurea under way. Perhaps the best find was a single Narthecium americanum, the yellow asphodel--extirpated from the rest of its range (where it never seems to have had more than a tenuous footing in historical times), its beautiful yellow spikes are no longer to be seen except in the watersheds of a few Pine Barrens rivers.

The herps were also on hand: I spotted a carpenter frog happily bobbing in the cedar water, and a green frog sheltering near some sundews at water's edge. (Sadly, no picture of the king snake that swam up to join the action shortly after Emily plunged into the fen.) The hot trek back along the old bog edges did reveal a Nuttallanthus canadensis popping up in the dry sand.

I went over to Webb's Mill afterwards and shot a few pictures I haven't logged yet, but by then I was out of water and ready to go home. Still, a good day, and an interesting return to the Pine Barrens after several years away.

Ingresado el 22 de julio de 2018 por choess choess | 26 observaciones | 0 comentarios | Deja un comentario

21 de julio de 2018

Ferns and Lycophytes of Muddy Run

After finishing work with Morgan on the morning of the 15th, I decided to turn northward along the Susquehanna to look for a different set of ferns. The mica-schist ranges of the River Hills provide dry, acid rock crevices, judiciously fed by seepage permeating through the outcrops, which favor Asplenium montanum and its allopolyploid descendants A. bradleyi and A. pinnatifidum. In the early 20th century, the hybrid A. × gravesii (A. bradleyi × pinnatifidum) was several times reported, but A. bradleyi itself is pretty hard to find these days. I know of some good spleenwort sites on local preserves, such as Kelly's Run and Tucquan Glen, but I also wanted to seek out some less-visited areas that might still harbor undiscovered treasures.

First, I checked on a known locality on the York County side of the river; a fallen tree made it tricky to access part of the site, but A. pinnatifidum and its backcross with A. montanum, A. × trudellii, were still occupying their familiar ledges, together with the usual tufts of A. montanum tucked into dry ledges and an A. platyneuron above in the woods.

From there, I headed up the river to visit the Muddy Run Wildlife Management Area. Muddy Run, a historic locality for spleenworts, has been dammed to form a pumped storage reservoir. However, the valley below the reservoir is not only preserved, but publicly accessible.

My initial foray down-valley seemed disappointing. Unlike the narrow gorges at Tucquan Glen or Benton Hollow, there didn't seem to be much outcrop in the hillsides. Ferns were the pretty standard woodland ones of the area; I didn't find marginal wood fern, a common haunter of rocky hillsides, until much further downvalley, testifying to the deeper soils.

As I bushwhacked around on the steep slopes downvalley, trying to avoid bouncing several hundred feet downhill onto the Port Road, outcrops and a xeric, acid forest began to reveal themselves. The reptiles were out in force, a box turtle and garter snake making their appearance. After photographing a chestnut stump sprout near a large outcropping, I tracked down some A. montanum in its crevices. There wasn't much else around...until I found a smaller outcrop nearby that was hosting a nice small colony of A. pinnatifidum. Dutifully crossing a valley and inspecting some more outcrops, I finally found the real prize of the day: a new station for A. bradleyi. It was probably known to the old-timers, but not reported anytime recently. Sadly, I didn't see any little plantlets around it; just an evergreen tuft clinging to its little niche in the schist. Still, it's always thrilling to be able to report another example of this rare fern.

Ingresado el 21 de julio de 2018 por choess choess | 23 observaciones | 0 comentarios | Deja un comentario

19 de junio de 2018

State Line Adiantum, Day 4

My last day in the field with Morgan was Friday, June 15. We returned to Pilot Barrens to capture an enormous patch of maidenhair fern in the shade at the edge of a grassland. Pilot is regularly fire-maintained, and has a beautiful, diverse array of serpentine grassland species, including some large, dense patches of few-flowered nutrush (Scleria pauciflora). I captured a few of them in observations: the ragwort and lobelia are just going out now but still make a lovely yellow-and-pale blue display. Fameflower is present on some exposed sites, but does not yet seem to be blooming.

The visit captured some interesting species. I found a shrub that may be shrubby St. John's wort (Hypericum proliferum) and a meadow spikemoss (Selaginella apoda or S. eclipes). I saw the latter on a barrens for the first time last month at Chrome. Maybe I've just been overlooking it, but it's interesting to see a lycophyte on the barrens. Normally we only see ground-cedar (Diphasiastrum digitatum) in piny woods over serpentine. Finally, and most interestingly, I found what seemed to be 3 stalks of wood lily (Lilium philadelphicum), which I see on occasion at Nottingham. This turns out to be SH for Maryland! I'll be going back to get better pictures and a more extensive survey.

All in all, a highly productive (7 sites in 3.5 days) visit which I hope will extend our knowledge of maidenhair fern ecology.

Ingresado el 19 de junio de 2018 por choess choess | 11 observaciones | 0 comentarios | Deja un comentario

State Line Adiantum, Day 3

June 14 was warmer and sunny, but less humid than the preceding day, with a bit of a breeze. Our destination today was the Cliffs of the Octoraro, where the maidenhairs join the other flora described by Pennell on the steep, rather stiltgrass-infested slopes above the creek. On the way, I was pleased to see that a mystery I noticed last year had broken into flower: it proved to be fly poison, Amianthium muscaetoxicum.

The setting at the cliffs is very interesting: a fairly rich forest with basswood growing in the soil brought down by the Octoraro, at the foot of the serpentine slope. Walking fern grows on mossy boulders of serpentine, and I saw foxglove beardtongue (Penstemon digitalis) growing at the edge of the creek. While inspecting the spleenworts (I'm still hopeful that a Scott's spleenwort will someday appear), I found an ebony spleenwort with an unusually shaped pinnae, perhaps damaged during growth.

After finishing the site assessment, we retraced our steps and proceeded to the magnesite quarry, where Morgan finished the assessment of the mine dump site while I made my way home by way of the powerline cut.

Ingresado el 19 de junio de 2018 por choess choess | 8 observaciones | 0 comentarios | Deja un comentario

17 de junio de 2018

State Line Adiantum, Day 2

June 13 was humid and cloudy. Morgan and I started at Nottingham County Park, where a logging operation is underway to remove pitch pine snags from the "front country". Fortunately, the Feldspar and Buck Trails remained open, giving us a path to maidenhair country.

We started by wading up Black Run from the Feldspar Trail to examine some small streamside colonies. Then we backtracked, went up the Feldspar Trail, and after a brief detour to examine the Mystery Hole, cut across Firebreak 10 and the serpentine seep to reach a streamside site on the Buck Trail. While Morgan was doing site assessment and soil samples, I explored down the length of Victory Run and documented a number of Adiantum pedatum colonies. The species is more abundant in the park than I had realized; perhaps it's less visible because there are fewer trails along drainages when compared to Goat Hill. The streamside was otherwise not especially interesting, except for a few rattlesnake ferns (Botrypus virginianus). A Chamaelirium luteum turned up near the site; I haven't yet found a site of high local density for these as at Goat Hill.

After a brief lunch, we ran southwest for Pilot Barrens, examining the perimeter of the two openings on the site, particularly the western one. Maidenhair was reasonably common in shaded areas; we had a false start near the entrance, and then found a larger and more interesting patch an an area of grassland reverting to greenbrier and brush. Here, there was essentially no canopy, and the maidenhairs growing on the side of a small gully had rotated their ultimate segments out of the plane of the blade, presumably a response to reduce sun exposure. Some daytime moths and odonates were present on the site; in addition to the usual skimmers, etc., I found a clubtail (ID'd by @scottking as a black-shouldered spinyleg) in a stiltgrass meadow near the Conowingo Creek. A small box turtle turned up in the brushy area.

One of the trees in the savanna forming the eastern opening appears to be a tupelo; not unknown on the barrens, but a little surprising to me in a savanna. On closer examination, the slopes around the eastern opening also proved to be rich in maidenhair ferns, disclosing one patch so large we decided to return for it on another day.

Ingresado el 17 de junio de 2018 por choess choess | 14 observaciones | 0 comentarios | Deja un comentario

State Line Adiantum, Day 1

My long-standing obsession with Adiantum pedatum on the State Line serpentine barrens has, in a sense, paid off. Morgan Southgate at UVM, who has been studying the entire A. pedatum complex on and around serpentine in Vermont, came south this week to survey and sample maidenhair from various sites on the barrens. I came along to point out some of the more interesting sites and identify local flora.

Our first day in the field was June 12, which we spent at Goat Hill Barrens. The first site surveyed was not far from the Rose Trail, on the upper waters of Pine Run. This is fairly typical habitat for Adiantum in the barrens; streamside in thicker alluvial soils, in a pine-red maple-catbrier or oak-red maple-catbrier forest where serpentine character is relatively limited. Saw the caterpillar of a definite tussock moth (Orgyia definita) near the site; common, but new for me, and carrying the interesting bristles characteristic of the genus.

We took a long loop through some of the forests and grasslands to the northwest of the powerline cut to see some of the characteristic serpentine flora, including quill-leaved fameflower (Phemeranthus teretifolius), which seems to be having a good year this year on various barrens (not yet blooming, though). Our path crossed a valley between two grasslands which abounds in fairy-wand (Chamaelirium luteum), now in spectacular bloom, and also contains some A. pedatum crawling some distance up the slopes in the forest. We emerged at the old magnesite quarry, where a population of maidenhair growing on the near-vertical slope of the mine dump was chosen for Site 2. A monarch butterfly was seen alighting nearby.

After carrying out the floral survey for Site 2, we backtracked towards a property corner below grassland 86, where a canopy gap near the stream shed light on a large, dense patch of maidenhair. (We also saw a nice Ophioglossum vulgatum site, discovered by Janet Novak in 2015, in the vicinity.) This was chosen as Site 3, and Morgan worked on surveying it as I left the field to go teach.

Ingresado el 17 de junio de 2018 por choess choess | 7 observaciones | 0 comentarios | Deja un comentario

21 de mayo de 2018

The cliffs of the Octoraro, redux

I really do visit other places, I promise. Back in September, acting on a tip from a botanical mentor, I revisited the cliffs of the Octoraro to look for walking fern again.

The name "cliff" is reasonably well-deserved. Though they're covered in oak forest, the slopes down to the Octoraro are very steep indeed, with rock outcrops and talus poking through the soil here and there. Sadly, the understory is thickly overgrown with stiltgrass. But a number of herbs continue to struggle gamely through the stiltgrass cover. What remains of the vegetation described in Pennell's classic article?

I didn't visit the high ridges that host the Goat Hill chickweed; it's still up there in a nearly impenetrable fortress of greenbrier. Pennell assigns three other species to the cliffs: "There in rock-crevices grows luxuriantly the harebell, Campanula rotundifolia, mingled with the equally northern snowy bedstraw, Galium boreale. The Canada lettuce, true Lactuca canadensis with the mid-blade and segments of the leaves linear and entire, further emphasizes the northern affinity of the flora of these cliffs. But Aster concinnus, with greener leaves and more ample sprays of smaller flowerheads than has A. laevis, its close kin elsewhere on the Serpentine, is of very local occurrence and has been little found anywhere in its range."

The harebell, though not abundant, still festoons the cliffs, together with quantities of wild columbine (Aquilegia candensis). I didn't see Galium boreale on the cliffs, but I run across it in rocky grasslands: at Goat Hill, Nottingham, and in a little barrens in Harford County, often quite abundant.

And this time, with slightly better directions, I found the walking fern! Asplenium rhizophyllum is growing, as is its wont, on moss-covered boulders, albeit of serpentine, not limestone. The colony is quite large. I took a number of pictures, and even found a place or two where ebony spleenwort, A. platyneuron is growing in juxtaposition to the walking fern. Alas, no hybrids were to be found. Nonetheless, it's always a good day when you find walking fern off of a calcareous substrate.

Ingresado el 21 de mayo de 2018 por choess choess | 5 observaciones | 0 comentarios | Deja un comentario

01 de diciembre de 2017

Dismantling Cheilanthes in the iNat taxonomy

Cheilanthes, as traditionally defined, is a large genus of ferns typically found in dry or rocky habitats throughout the world. It belongs to a group known as the "cheilanthoids", now typically recognized as subfamily Cheilanthoideae of family Pteridaceae. Defining natural genera in the cheilanthoids has proven to be very difficult. Adaptation to dry environments has driven many unrelated species to adapt similar morphologies, so many of the diagnostic characters traditionally used to separate Cheilanthes from Notholaena and other, similar genera do not reflect evolutionary relationships. (See this summary for more details.)

The use of molecular phylogenetics has allowed researchers to begin reclassifying the cheilanthoids into monophyletic genera, although it is still very difficult to find sets of morphological characters to define them. Work over the past decade or two has concentrated on American cheilanthoids, which are most diverse in Mexico and the southwestern United States, so naturalists in those areas will see the greatest effects from these taxonomic changes. These generally transfer species formerly placed in Cheilanthes into other genera: Notholaena, Gaga, and Myriopteris.

While it's not generally iNat policy to update taxonomy directly from primary literature, some of our secondary sources (e.g., Calflora) have already started using these changes, and I think it is now a suitable time to implement them. Three papers in particular are important:

Some taxon swaps into the new genera Gaga and Myriopteris have already taken place, but I intend to complete the swaps into these genera.

What does this mean for identifiers?

In the United States, almost all Cheilanthes species (except C. leucopoda) will be transferred into Myriopteris. (Gaga arizonica and G. kaulfussii have already been swapped.) In Mexico, a few species will remain in Cheilanthes, but most will be swapped to either Myriopteris or Gaga.

A few general rules (not always accurate) can be followed for generic placement in Mexico and the southwestern US. If the underside of the leaf is coated in farina (a powdery or waxy secretion), it belongs to either Notholaena, Pentagramma or Argyrochosma. Leaves of Gaga tend to have slender, highly dissected segments with wide gaps between them, and, with the notable exception of the common G. kaulfussii, which is glandular-hairy, have shiny dark rachides (leaf axes) without hairs. In many Myriopteris, leaves are highly dissected into rounded, bead-shaped segments with little space between them, and hairy rachides. However, many are less highly dissected, comparable to the triangular-bladed members of Notholaena. The most common species in Mexico to be transferred, Cheilanthes bonariensis, which will become Myriopteris aurea, resembles an Astrolepis but covered with hairs rather than scales on the upper surface. If you can't identify a specimen, it can always be left in subfamily Cheilanthoideae for examination by others. Identification to species level in these genera requires careful attention to the abundance and type of hairs and scales on both upper and lower surfaces of the leaves, and on the leaf axes and leaf bases. Photographs showing both sides of the leaf at close range, so that hairs and scales can be examined, are very helpful, whether or not the leaf is fertile.

I don't think it will be very hard for most casual users to split most observations among Myriopteris and Gaga, rather than Cheilanthes s.l., and I expect that the people who can regularly key these out to species will be familiar with these changes in nomenclature, and perhaps even more comfortable with the new names.

@alexiz , @aztekium , @net8a , @juancarloslopezdominguez , @pioleon , @elizatorres , @tindalo , @gonzalezii , @idlegrraphics , @lexgarcia1 , @biolram , @leopoldohurtado , @aspidoscelis , @stevejones , @billdodd , @nathantaylor7583, @mariposasazules , @joseantonioap , @najera , @juancarlosgarciamorales1 , @manesalinas , @carloscarrera , @jrebman, @ck2az , @finatic , @alex_abair I'm alerting you as you have made many of the existing identifications of cheilanthoids in Mexico and the North American southwest. I have asked @bodofzt to help with Spanish translation. Please spread the word among local observers. I plan to make the changes in a few days unless there's unexpected opposition.

Thanks to @kathleenpryer , @crothfels , @fayweili , @grusz, and @gyatskievych, all of whom have contributed significantly to our present understanding of the cheilanthoids.

Updated with a translation kindly supplied by bodofzt:

En su definición tradicional, Cheilanthes es un extenso género de helechos que normalmente habitan ambientes secos o rocosos a nivel mundial. Pertenece a un grupo conocido como "cheilanthóideas" (o "helechos labiados"), que actualmente se suelen reconocer como la subfamilia Cheilanthoideae de la familia Pteridaceae. La definición de géneros dentro de esta subfamilia ha resultado muy difícil. La adaptación a ambientes secos ha llevado a especies no emparentadas a adoptar morfologías similares, por lo que muchas de las claves de identificación que se emplean tradicionalmente para separar Cheilanthes de Notholaena y otros géneros similares no reflejan relaciones evolutivas. (Ver este resumen para mayor detalle.)
El uso de la filogenética molecular ha permitido a los investigadores empezar a reclasificar las cheilanthóideas en géneros monofiléticos, aunque sigue siendo bastante difícil encontrar conjuntos de caracteres morfológicos para su determinación. Durante los últimos 10 a 20 años, la investigación se ha enfocado en las cheilanthóideas americanas. Estas tienen un foco de diversificación en México y el suroeste de los Estados Unidos, por lo que los naturalistas en estas regiones verán los mayores efectos de estos cambios taxonómicos. Estos generalmente transfieren las especies anteriormente colocadas en Cheilanthes a otros géneros: Notholaena, Gaga y Myriopteris.
Aunque en iNat/NaturaLista generalmente no se adoptan cambios taxonómicos directamente desde la literatura primaria, algunas de nuestras fuentes secundarias (por ejemplo, Calflora) ya han comenzado a aplicar estos cambios, y creo que ahora es el momento adecuado para implementarlos aquí. Son tres los documentos de importancia particular:
Ya se han realizado algunos pocos cambios taxonómicos hacia los nuevos géneros Gaga y Myriopteris, y tengo la intención de completar las transferencias hacia estos géneros.
¿Qué significa esto para los identificadores?
En los Estados Unidos, casi todas las especies de Cheilanthes (excepto C. leucopoda) serán transferidas a Myriopteris (Gaga arizonica y G. kaulfussii ya han sido transferidas.) En México, unas pocas especies permanecerán en Cheilanthes, pero la mayoría serán transferidas a Myriopteris o Gaga.
Se pueden seguir algunas reglas generales (aunque no siempre fidedignas) para la determinación de géneros en México y el suroeste de los Estados Unidos. Si el envés de la fronda está cubierto de farina (una secreción polvosa o cerosa), pertenece a Notholaena, Pentagramma o Argyrochosma. Las hojas de Gaga tienden a los segmentos delgados, altamente bisegmentados y con amplios espacios entre los segmentos; con la notable excepción de la común G. kaulfussii, donde es glandular-piloso, tienen raquis (ejes de la fronda) oscuros, brillantes y sin pelo. Muchas especies de Myriopteris tienen hojas altamente diseccionadas en segmentos redondeados, en forma de microesferas con poco espacio entre ellas, y raquis velludos. Sin embargo, muchos son menos bisegmentados, sino más similares a los miembros de hoja triangular de Notholaena. La especie mexicana más común que será transferida, Cheilanthes bonariensis, que se convertirá en Myriopteris aurea, se asemeja a un Astrolepis pero cubierto, en el envés, de pelo en vez de escamas. Si hay problemas para identificar el género, siempre se puede dejar en la subfamilia Cheilanthoideae para que otros examinen la observación. La identificación a nivel especie de estos géneros requiere una cuidadosa atención a la abundancia y tipo de pelos y escamas, tanto en el haz y el envés de las hojas, como en los ejes y las bases foliares. Son muy útiles las fotografías que muestran acercamientos de ambos lados de la fronda, para examinar pelos y escamas, sin importar si la hoja es fértil o no.
No creo que sea muy difícil para la mayoría de los usuarios ocasionales separar la mayoría de las observaciones entre Myriopteris y Gaga en lugar de Cheilanthes s. l., y espero que las personas que regularmente identifican estas especies estarán familiarizadas con estos cambios de nomenclatura; tal vez incluso se sientan más cómodas con los nuevos nombres.
@alexiz , @aztekium , @net8a , @juancarloslopezdominguez , @pioleon , @elizatorres , @tindalo , @gonzalezii , @idlegrraphics , @lexgarcia1 , @biolram , @leopoldohurtado , @aspidoscelis , @stevejones , @billdodd , @nathantaylor7583, @mariposasazules , @joseantonioap , @najera , @juancarlosgarciamorales1 , @manesalinas , @carloscarrera , @jrebman, @ck2az , @finatic , @alex_abair: Los etiqueto puesto que han hecho muchas de las identificaciones existentes de cheilanthóideas en México y en el suroeste de Estados Unidos. Le pedí a @bodofzt que me ayudara con la traducción al español. Por favor, corran la voz entre los observadores locales. Planeo hacer los cambios en unos días, a menos que me encuentre con una gran oposición, misma que no espero.
Agradezco a @kathleenpryer , @crothfels , @fayweili , @grusz, and @gyatskievych, quienes han contribuido significativamente a nuestra actual comprensión de las cheilanthóideas.

Ingresado el 01 de diciembre de 2017 por choess choess | 13 comentarios | Deja un comentario

26 de octubre de 2015

On the cliffs of the Octoraro

For several years, I've been trying to get at a walking fern locality in the western part of the Goat Hill tract of William Penn State Forest. It's located above the steep southwest bank of Octoraro Creek, overlooking the bottomlands across the creek where Wood's Mine once tunneled 720 feet down along a chromite vein. These are the "cliffs of the Octoraro" once studied by Francis W. Pennell.

Pennell may have reached the western cliffs by what maps still show as Gray Horse Road, but this old county road has since been abandoned and turned to private driveways. While hunting Adiantum for my research, I tried to reach this area by bushwhacking down Pine Run from the Rose Trail and following the Octoraro downstream. That bushwhack was something of a nightmare in and of itself; below the mouth of Pine Run, an irregular fisherman's trail clings to the steep slope, invaded by stiltgrass but still sprouting Adiantum and Campanula rotundifolia for some distance, crosses an alluvial terrace with relatively open woods—and only then does one reach the truly steep slopes of the "cliffs". Even when the journey to the Octoraro was eased by cutting across a neighboring property, I've never been able to penetrate any great distance along the cliffs before turning around in enervated frustration. I did briefly visit the site, after asking permission from one of the neighbors to cut up the old Gray Horse Road, but I was busy sampling Adiantum and didn't have time to mount an extensive search for walking fern.

Frankly, I've always found this part of Goat Hill a bit unsettling. I'm not usually bothered by the prospect of bushwhacking or being "deep in the woods", but even when you can see the old Wood farm right across the creek, there's a feeling of remoteness and isolation here. I think it's mostly an effect of the terrain and the vegetation: there's a lot of up and down just getting here, often over narrow and treacherous trails, and the close embrace of the greenbriar, in many places, doesn't really leave you with an alternate route out. If you struggled in, you'll have to struggle back out again.

Anyway, it turns out that there's an alternate route down to the terrace along the Octoraro that branches from the Rose Trail and is being maintained, in part, by the Boy Scouts of Camp Horseshoe. I figured that if I could follow a trail most of the way to the cliffs, I'd be less worn out and ready to tackle the journey, and as a bonus, I might find some of the Goat Hill chickweed that grows at the tops of the gentler eastern bluffs. The trail runs, in part, south of the contact line between the serpentinite that underlies Goat Hill and the adjacent metagabbro. Off serpentine, the deciduous forest is open and largely greenbriar free, and at this time of year, full of delightful fall color. I noticed a southern red oak leaf (Quercus falcata); it's uncommon in Pennsylvania and doesn't come much further north. I've seen it growing in the oak groves around the Nottingham parking lots as well. There was indeed some of what I believe is the "very hairy chickweed" (Cerastium velutinum var. villosissimum) growing along the trail—this variety deserves a closer genetic examination, which I hope I can work on in the next year or two.

It wasn't very far from the trail to the edge of the high western cliffs, and I quickly found going just as difficult as ever. The slopes are high, steep, and for the most part, covered in greenbriar (Smilax rotundifolia). Drainages and game trails open narrow gaps, often full of stiltgrass (Microstegium vimineum), in the greenbriar, which the explorer perforce must follow. Much of the greenbriar is sparse enough, and no higher than knee height, that it can be forced with some annoyance, but the thickets atop the bluffs are denser and taller. In the open drainages, northern maidenhair fern (Adiantum pedatum) is common, and it seems as though every substantial rock has one or more ebony spleenworts (Asplenium platyneuron) growing on it. After 20 minutes or so spent struggling along the bluffs, I realized that at this rate of progress, I wasn't going to reach my objective, and might not make it out before dark, either. Struggling upwards, I made the questionable decision to try to strike south for the state forest boundary (close, here, where the creek swings close to the Maryland line) and a possible firebreak to follow. This involved forcing my way through the lush greenbriar at the bluff top by such openings as I could find (one of which held a nice clump of cranefly orchid). Amazingly, the gamble paid off without too much blood loss; there wasn't a firebreak, but I got south of the geologic boundary again and could travel west along the boundary blazes through a relatively open forest with spicebush and pawpaw in the understory.

With my time running out, I finally reached an insurmountable obstacle in the form of "Deep Hollow": a little stream draining the country behind the bluffs has cut a steep vertical-sided ravine through the cliffs to empty into the Octoraro, and I didn't have the time left to pick my way around or across it to reach my site. The eastern slopes of Deep Hollow where it breaks through the cliffs are covered in loose rock which, though presumably ultramafic, doesn't support greenbriar; I peeked around the cliff, and the steep slope down to the Octoraro was mostly bare with scattered Christmas ferns (Polystichum acrostichoides). On the southern and western sides of the slope, above the hollow, the rocks were usually mossy and the predominant herb was marginal wood fern (Dryopteris marginalis) with the occasional maidenhair; the ebony spleenworts didn't seem to have taken up residence.

I wound up cutting back more or less due east, following the state forest boundary through open, non-serpentine woods, until I got back to my original trail and I could follow the established trail network out. The colors on the barrens are beautiful this time of year; the russet of the little bluestem (Schizachyrium scoparium) nicely complements the fall foliage. I came back up the powerline cut with the sun setting at my back and reached my car in the twilight. What a trip!

Ingresado el 26 de octubre de 2015 por choess choess | 7 observaciones | 3 comentarios | Deja un comentario

29 de marzo de 2015

White Clay Creek walk, March 28

I've been out scouting recently in preparation for doing some wildflower hikes in the White Clay Creek parks. I don't have pictures from my March 21 hike (I'll probably go back and get some), but I was fortunate enough to find all three of what I think of as our "winter orchids": orchids that stay in leaf all winter. One of these is Goodyera pubescens, downy rattlesnake-plantain, which holds its leaves year-round. A relatively common one, although I don't see it that frequently in the Delaware Piedmont. The other two carry their leaves through winter to capture the sunlight no longer blocked by the canopy, but lose their leaves before flowering in summer. The more common of the two is Tipularia discolor, the cranefly orchid, which usually shows a striking magenta-purple beneath (although I have seen what appears to be f. viridifolia, which is largely green beneath, with traces of purple on the venation). These often show raised purple dots on the upper surface. The third, to my happy surprise, was Aplectrum hyemale, puttyroot, a rare species in Delaware. It has a distinctive "pinstriped" appearance, with thin parallel white veins running the length of the leaf. A little scouting revealed a very large quantity of puttyroot spread over the site. The whole hike more or less lies within a tulip-tree forest with an unimpressive shrub layer (mostly Rosa multiflora); most of it was wooded in 1937, but I think this site would have been very close to the wood edge. It isn't what I'd think of as rich, high-quality woods, but I found a large colony of Aplectrum in similar habitat elsewhere in the park a few years ago. Also a few leaves of Anemone americana, hepatica, but the puttyroot really took the prize.

My walk on the 28th, which is documented, was up on the Pennsylvania side (White Clay Creek Preserve). A trail on the east side of the creek climbs the edge of a steep, northwest-facing slope covered in an oak-heath forest. (The oak-heath forests I see have a heavy admixture of beech; I assume this is due to some combination of reduced fire and deer browse on oak seedlings.) While strolling along in one direction, I noticed some Epigaea repens sprouting at trailside; another happy find, as I don't see that very often along the Pennsylvania-Delaware border. When I came back to take a picture, it took me about four tries to find it again, even with GPS coordinates...elusive!

My friend Janet Ebert has had me looking for clubmoss in this part of the Piedmont lately (not that it takes much); she feels the Delaware Piedmont is losing most of its clubmosses as earthworms invade the forests and break down leaf litter, so I've been on the lookout for Dendrolycopodium and the like. I found several little sprigs of shining clubmoss, Huperzia lucidula, growing along the trail in one area. Huperzia s.s. produces gemmae which allow it to disperse vegetatively, and to my excitement, the sprig that I photographed appears to be growing from a gemma. Naturally, I looked upslope for a possible source, but without success; the slope is steep and bare, and a parent colony would have been obvious. There's a very large colony of H. lucidula about a third of a mile downstream; maybe the source is closer, but regardless, it seems like the gemmae have more dispersal potential than I would have assumed. I took pictures of some of the common oak-heath-beech understory flora.

Elsewhere in the preserve, I did stumble upon a patch of Dendrolycopodium obscurum, as yet unfazed by worms. I'm surprised I hadn't noticed it before, or maybe I just forgot. I also took a picture of Polystichum acrostichoides, the very common Christmas fern, helping hold down a slope nearby. They're very common on steep, eroding slopes, perhaps because they provide good habitat for gametophytes.

Ingresado el 29 de marzo de 2015 por choess choess | 8 observaciones | 0 comentarios | Deja un comentario