Branching in Camissonia seedlings

Branching in Camissonia lacustris begins at the cotyledonary node (at red arrow, the cotyledons at yellow arrows, 80 day old seedlings). At this age, the cotyledons are still fully functional and are, after post germination maturation, identical to the first formed foliage leaves. Precious branching is not uncommon throughout angiosperms, indicating that the feature is adaptive in specific environments, and can be selected out of a genome again and again. In Onagraceae, within Camissonia as delimited by Raven (1969), the differences in growth features between rosette annuals (now treated within Chylisma and Eremothera) and Camissonia sensu stricto are manifold, and support the dismemberment of the Raven genus concept. Done. Remember, Raven dismembered the Munz' genus Oenothera with the occasional raised eye-brow typical of the pre-DNA era of systematics. In thinking about the expression of branching control in Camissonia seedlings, the feature of flowers at basal nodes in Gayophytum, where G. diffusum, which branches distally and is very common, contrasts to G. decipiens and its basal branching and relative rarity comes to mind: perhaps the grazing lips of a herbivore ought to be brought into the mix: lateral gene transfer? {by that I mean that there is a distance above the ground surface which grazing influence does not penetrate, the lip-o-the-grazer distance. Branch below that distance, and survive.

Plants are cool!

Top: Camissonia sierrae ssp. alticola from Little Yosemite Valley, DWT #20938 16 July 2010 Bottom: Camissonia lacustris Wawona (vouchered by DWT 18082, JEPS109727)

There are distinct differences in the seedlings of two species of Camissonia in the Yosemite Region. In Camissonia sierrae ssp. alticola Little Yosemite Valley, the colytedons are of quite different shape from those in C. laucustris Wawona, as pictured (red arrow in each photo).

In C. sierrae, the cotyledons are initially rhombic in shape, but later become lanceolate; they lack ciliate margins which can be seen on the first foliage leaves, and are entire margined. The plants at 7 weeks of age form a distinct rosette.

By contrast, C. laucustris Wawona produces cotyledons which are linear and distinctly emarginate. Moreover, during development, their cotyledons elongate markedly, becoming 15-20 mm long and are similar to the first foliage leaves.

The differences in early development of these two species makes their seedlings relatively easy to identify, if one could find them in the field.

More species need to be grown out to ascertain if these differences form morphological classes within the genus, and if the morphological differences have classificatory and/or phylogenetic value.

central Sierra Camissonia seedlings

Top:

Camissonia sierrae ssp. alticola

Little Yosemite Valley

DWT #20938 (JEPS, YM) 16 July 2010

Bottom:

Camissonia sierrae ssp. alticola
Little Yosemite Valley

DWT #20938 (JEPS, YM)

There are distinct differences in the seedlings of two species of Camissonia in the Yosemite Region. In Camissonia sierrae ssp. alticola Little Yosemite Valley, the colytedons are of quite different shape from those in C. laucustris Wawona, as pictured (red arrow in each photo).

In C. sierrae, the cotyledons are initially rhombic in shape, but later become lanceolate; they lack ciliate margins which can be seen on the first foliage leaves, and are entire margined. The plants at 7 weeks of age form a distinct rosette.

By contrast, C. laucustris Wawona produces cotyledons which are linear and distinctly emarginate. Moreover, during development, their cotyledons elongate markedly, becoming 15-20 mm long and are similar to the first foliage leaves.

The differences in early development of these two species makes their seedlings relatively easy to identify, if one could find them in the field.

More species need to be grown out to ascertain if these differences form morphological classes within the genus, and if the morphological differences have classificatory and/or phylogenetic value.

Camissonia lacustris

Where is the type population of Lewisia congdonii?

Basionym: Oreobroma congdonii Rydb., N. Amer. Fl. 21(4): 322. 1932.

Protologue: "Type collected on the Hennesay [sic] Ranch, Mariposa County, California, May 31, 1883, Congdon (Dudley herb. Stanford Univ. 45334)."

The type and UC/JEPS isotype specimens are labeled "Hennesey Trail", which indicates that the specimen was taken in the ascent from Henness Ranch, located on the floor of the canyon in present day El Portal, up the south rim of the canyon. The Henness Trail appears on the 1897 edition of the Yosemite 30-minute USGS quadrangle, but is not named until the reprinted 1929 edition. The trail ascended the canyon wall and the exact station of the type collection has never been relocated.

The MIN Isotype is labeled "Hite's Cove and Yosemite Trail"

At one time, Hennesey Trail was a major but secondary route for visitors to gain access into Yosemite Valley. The trail is shown on the 30-minute USGS quadrangles: on the 1887 first editon, and on other editions issued between 1903 and 1911, the trail is depicted, but not named. On the 1923 edition, the trail name appears. On the 1956 first edition of the 15-minute quadrangle, the trail is no longer mapped. In that era, visitors using the Yosemite Valley Railroad, which opened in 1907, would come to El Portal and thence would be taken by mule train to Yosemite Valley via the Hennesey Trail, and that fact would be consistent with the trail having been mapped with a placename on the 1923 map.

Congdon, being a lawyer traveling through the region, is well documented by his trail of specimens to have visited much of Mariposa County, and no doubt would have rode horseback up the trail into the Valley via that route. Congdon's labels for that period bear out his route, a few examples:

May 31, 1883
MIN235214 Iris hartwegii
MIN235935 Hosackia crassifolia
MIN236268 Draperia stystyla Hite's Cove and Yosemite Trail
MIN237456 Clarkia heterandra Yosemite Trail
MIN238487 Calyptridium umbellatum Hite's Cove and Yosemite Trail and Yosemite Valley.

June 1, 1883 – pretty clearly, Congdon went into Yosemite Valley, based on these labels
MIN231619, MIN237891, MIN238314, MIN238976 Yosemite Valley
MIN235470 Yosemite Trail
MIN236100 River Trail to Yosemite Valley
MIN237643 Yosemite Valley and Glacier Point
MIN238521 Cascades, Yosemite Valley
MIN238593 Yosemite Trail, Merced River,
MIN238976 Yosemite Valley
MIN239486 Cascades and Yosemite Valley

Propositon: on this basis, the type station for Lewisia congdonii is probably NOT the well know population on the rocks at the base of Pigeon Gulch, along present day Highway 140. It is more probable that the type specimen was collected along the ascent route of the Hennessay Trail, which would suggest that another, presently uncodumented population is located on the steep, north facing wall of the Merced Canyon, perhaps even near Chinquipin Falls, on the present day Yosemite National Park boundary.

Exclusively vegetative reproduction in Pennisetum clandestinum (Kikuyu grass) in Caifornia

Reproduction in kikuyu grass in coastal central California appers to be largely vegetative. In years of searching for flowering plants, I have never seen anything other than vegetative growth. The California Invasive Plant Council website treatment of this taxon notes that it can be spread via rhizome and stolon fragments. An amplification on what constitutes the invasocore unit of dispersal is in order: Pennisetum clandestinum produces swollen nodes which can also support dormant roots within the leaf sheaths. The entire nodal structure is the unit of dispersal, not in my observation the stolon fragments. Stolons are about 8 mm diameter or so, but when fragmented, the internodal segments do not seem to take.

The unit of dispersal might be termed a nodochore.

This coarse grass is a major invader of the coast side of the fairways at Pebble Beach, where its abundance vs. inland locations as opposed to Festuca rubra, indicates a significant degree of tolerance of salt spray.

Oak catkins and the carbon cycle

Accounting for pathways in the carbon cycle is now much like the state of cosmology before big telescopes: Hubble saw something in data, and, a few twists and turns later, PRESTO – the Big Bang Theory. Much if is not most of Earth's biosphere carbon stores reside in forests, either above ground or in soil. Being that I live in a forest (Sequoia sempervirens, Psedostugs menziesii, Quercus sheevei), and being that I attempt (vainly, perhaps) to manage organic matter accumulation on my roof (failed, miserably) and yard (difficult, but manageable), I can offer up a pathway observation which might be of note in illustrating the difficulty of modeling the carbon cycle. Acorn cups, acorn shells, and male catkins.

In the context I wish to broadcast, these four pathway compartments hold small stores of carbon, but the residence time therein is considerable, and thus in a model may be of sufficient magnitude to influence model verification. Oak acorns get eaten: the shells (pericarp) last for years. Their abundance is not minimal in some instances, but their decay rate seems glacial.

A modeler might not want to dwell on the problem of stored carbon contained in spent oak inflorescences, assuming the matter trivial. They, however, do not decay rapidly, they certainly last for more than a given year because in spring, when the oaks flower, for a period one can find last yr inflorescences scattered about after a big blow. Inflorescence parts are retained in the canopy for more than a single growing season.

Acorn cups of Q. shrevei seem to have a half-life that exceeds that of the acorn shells: perhaps by a year.

In redwood forest, the female cones of Sequoia sempervirens also behave much like Q. shrevei acorns: they are small, but last for years.

These little vignettes are just that – vignettes particular to a particular forest type. But the problem of vignettes is just that: in accounting for the carbon budget of forests, are little seemingly trivial stores such as acorn cups, female cones, and inflorescence remnants trivial, or do they warrant sampling. In my view, sampling the trivial pathways to demonstrate they are in fact trivial is not trivial.