notes View of a flower from behind. [Unfortunately, the bud at the end of the pedicel from the node above that of the open flower was between the lens and the center of the open flower...causing a blur that obstructs the base of the open flower. I didn't notice that in the field, and took no alternative shots!]This was my first 'live-in-habitat' encounter w/ N. morefieldii...it was a delight!
As usual with Nemacladus, it was initially difficult to 'see' these plants in the field...even after squatting low to bring one's eyes closer to the ground (from the relatively ''high altitude'', for Nema's, of standing on one's feet!). But after bending down & locking-in on the gestalt of the plant's delicate architecture & flowers...a perceptual/contextual adjustment kicked in...and other nearby Nemacladus plants started to become apparent ;-).
Nemacladus morefieldii was only recently described, in the paper Morin & Ayers(2020). Its diagnostic characters include:
1) The corolla in this species is 'non-resupinate' ...i.e. not twisted by 180° along the pedicel, as in many other species in the genus. Thus the upper [= adaxial] corolla lip has three lobes, and the lower [= abaxial] lip has two lobes. Note that all the lobes here are separated nearly to the base (i.e. there's no appreciable corolla tube);
2) Note that, as usual, the sepals alternate behind the corolla lobes. There are two upper [=adaxial] sepals, two lateral sepals, and one lower [= abaxial] sepal (i.e. between the 2 lobes of the lower corolla lip). Morin & Ayers(2020) refer to the two upper sepals as ''central sepals'', and the two lateral sepals as ''flanking sepals'' (since they flank the upper corolla lip). In N. morefieldii the two flanking sepals are typically appreciably longer & wider than the two central sepals. This is usually a conspicuous supporting character...though it can vary quite a bit, and in some flowers can even appear nearly null (as in the image herein);
3) The most conspicuous diagnostic character for N. morefieldii is that each of the three upper corolla lobes has a distinctive reddish-brown marking along its apical margin in the rough shape of a 'chevron' (= inverted 'V'). The chevrons can vary...from 'quite-narrow', to 'centrally-bulging'...but are always concave along their inner margins.
The 5 images below illustrate the above characters...though note that in the 1st image the ''flanking sepals'' are near the 'narrow end' of the range of variation for that character (as is also the case for the specimen in my post here). Click the thumbnails to link to the original posts (by Matt Berger & Steve Matson):
Compared to other Nemacladus species, N. morefieldii is most similar-looking to N. orientalis...which is the most widely-distributed species in the genus, and with which N. morefieldii can co-occur. In N. orientalis, the apices of the upper three corolla lobes have a solid, reddish, diamond- or kite-shaped marking that is convex along its inner margin...in contrast to the more margin-hugging, concave chevron of N. morefieldii. And the sepals are more nearly equal in size. The flowers of N. orientalis are also larger (2.6–5.0 mm per Jepson eFlora) than those of N. morefieldii (2.2-3.4 mm per Morin & Ayers(2020))...but all Nemacladus species have fairly tiny flowers by usual standards, so this can be hard to perceive unless you find both species growing side-by-side, as seen in Matt B's post below: