notes The body (and legs?) of a small insect appear to be visible in the open flower at far right. (Perhaps it perished when the corolla filled with rainwater earlier that day?)These plants were growing on a melange of rough, angular rocks, stones, and pebbles...held together by silty soil...all derived from the local limestone parent material. The habitat was a relatively open, somewhat steep, west-facing mountain slope that was rather unstable to walk on...with scattered blackbrush (Coleogyne ramosissima) & pinyon pine (Pinus monophylla). The local herbaceous plants were quite sparse but included Bromus tectorum :-(, Chaenactis macrantha, Prenanthella exigua, Eriastrum eremicum ssp. eremicum and others...including at least one individual of Nemacladus sigmoideus and one of N. orientalis.
Once the truly tiny size of the Nemacladus californicus plants really sunk into my consciousness, I began to see lots more of them nestled in the crevices between small rocks as I spot-searched within an area of roughly 150' by 100'. I'd estimate there were at least many hundreds there, and more beyond...though I'm guessing that density is not typical, as this year has had unusally high & frequent rainfall and Nemacladus species appear to be having an exceptionally abundant crop in many CA locales.
Many plants had more than one open flower, some had numerous withered flowers, and some had developing flower buds. My impression was that at this locale it was beyond the middle of the flowering period for the local population...but without systematic monitoring of the population I don't really know. Also, populations occur at various elevations in the larger general area, so overall flowering may extend over an appreciable time interval...especially in a year like this where continuing rain events may prolong survival & growth of these annuals.
The photos here were taken late in the afternoon and it had rained in the morning. Most plants had at least one 'fresh-looking' open flower, i.e. with bright-yellow paddle-like appendages at the base of the filament tube and glistening translucent rods. But in other open flowers those parts appeared comparatively dull. I don't know whether that dullness was from aging, or perhaps from being sullied by the rain...or a combination of the two? I wonder how frequently new flowers open per plant? And how long a given flower stays open?
In Nemacladus flowers the staminal filaments are fused above their bases into a tube, and at the bent tip of that tube the introrse anthers are connivant and form a ring. As the style elongates within the filament tube, the anthers mature and dehisce first, and eventually the stigma is pushed out the top of the tube and becomes receptive. But how long does this take: hours, or days? And how much of the pollination is insect-mediated (and by which insects?), versus facultative selfing? Do flowers promptly wither once pollinated? How abundant is seed set, and what is the longevity of seed in the soil bank? These are just some of many interesting questions to ponder ;-).
In addition to the Jepson eFlora treatment of N. californicus, one can read more on this species under the former combination Parishella californica in McVaugh(1942) and Gray(1882).
Found in the vicinity of Valerie Soza's 1998 voucher here...the population still seems to be going strong :-)