Cassiinae pt 1 NY-Botanical_gardens_Vol. 35_1 - Copy.pdf - Antbase

284 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 35
to Quay County and the White Mountains, s. just into n.-e. Chihuahua, centr.
Coahuila, and n.-centr. Nuevo Leon; one starion w. of the Rio Grande in s.-w.
New Mexico (Sierra County).—Fl. IV-IX(-X).
A senna widespread and famUiar in the arid grasslands and mesquite plains of
southwestern United States and northeastern Mexico, where it is disringuished
from other bifoholate Brachycarpae by the long, proporrionately narrow leaflets
combined with a hnear style. It is closely akin only to S. mensicola, next follow­
ing, which see for comment.
85. Senna mensicola (Irwin & Barneby) Irwin & Barneby, Phytologia 44(7): 500.
1979. Cassia mensicola Irwin & Barneby, Sida 6(1): 12. 1975.—
"MEXICO. San Luis Potosi: Charcas, VII-VIII. 1934 (fl, fr), C. L
LundeU 5i45."—Holotypus, CAS! isotypi, MEXU, TEX!
Low erect or diffusely assurgent herbs, perennial but precociously flowering
and of only few seasons' duration, the simple or few-branched stems arising from
slender blackish root, at anthesis 0.5-2(-2.5) dm, together with lf-stalks and axes
of inflorescence densely pUosulous with retrorsely descending or accumbent
shorter hairs mixed with fewer ascending coarser setules up to 0.4-1 mm, the
foliage either subconcolorous, dark green on both faces, or gold-green above,
always densely subappressed-pUosulous above and below, the axiUary few-fld racemes
a Uttie shorter or longer than the If, never aggregated into a terminal
panicle.
Stipules widely spreading-ascending hnear-attenuate (3-)4-9 x 0.4-0.6 mm, at
first herbaceous becoming dry and deciduous before the associated If.
Lvs (2-)2.5-5.5(-7) cm; petiole including discolored but scarcely swollen pulvinus
10-27(-32) mm, at middle 0.4-0.7 mm diam, the shallow ventral groove
almost closed; gland erect from between the 1 pair of lfts ± at right angles to
petiole, shortly stipitate, in profile 1.2-1.8 mm, the stipe puberulent, the slenderly
lance-fusiform acute head 0.1-0.2 mm diam; Lfts narrowly oblong or oblong-eUiptic
obtuse mucronulate, the larger ones of a plant 16^5(-50) x 6-15(-19) mm,
2.4-3.3 times as long as wide, at base deeply cordate on proximal and cuneate
on distal side, the margin plane, the upper face of blade veinless, the midrib
prominulous beneath and there giving rise on each side, or only on the broader
side of blade, to 2-6 weak ascending secondary veins, these expiring weU within
the margin.
Racemes l-3(-4, commonly 2)-fld, the short axis and peduncle together
(2-)2.5-5(-6) cm; bracts hnear-lance-attenuate 2.5-5 mm, becoming dry but only
tardUy deciduous; pedicels 4-10(-12) mm; fl-buds subglobose becoming obovoid,
pilosulous; sepals thin-textured pale green, scarcely or little graduated, in outhne
elliptic or elliptic-obovate obtuse, the inner ones 5.5-8.5(-9.5) x 2.2-3.8 mm, all
deciduous with the coroUa; petals glabrous, yellow drying whitish dark-veined,
broadly oblanceolate or obovate-cuneate (11-)12-16.5(-18) x 6-12 mm; androe­
cium glabrous, funcrionaUy 7-merous, the staminodes narrowly spatulate, the 7
fertUe members homomorphic but a trifle accrescent toward abaxial side of fl, the
filaments 1.8-3.1 mm, the oblong, genriy incurved anthers 2.6-3.6 x 0.6-0.85
mm, at apex abruptly conical and there dehiscent by a single introrse pore, the
anther-waUs thin-textured bicolored, castaneous along the connecrival grooves,
lateraUy yeUow; ovary densely white-pUosulous; style glabrous, narrowly cyhndric,
incurved from ovary but thence straight or almost so, (1. l-)l .4-2.1 x 0.25-0.3
mm, the symmetricaUy terminal stigmatic cavity ciUolate; ovules 34^2.
Pod ascending sessUe, in outUne, compression, texture and color essentiaUy