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

1982] CASSIINAE—SENNA 287
Stipules at first ascending, often spreading-reflexed in age, narrowly lance-at­
tenuate, Unear-caudate or setiform 2.5-7 x 0.3-0.6 mm, becoming dry and tardily
deciduous.
Lvs 1.5-5.5 cm; petiole (0.5-)0.8-2.6(-3.2) cm, at middle 0.3-0.65 mm diam,
obscurely ribbed dorsally, the ventral groove shallow and almost closed; gland
between the one pair of lfts stipitate or subsessUe, in profile (0.5-)0.6-1.4 mm,
the stipe usually pilosulous, slender or rarely incrassate and thicker than the
head, this (much eaten) slenderly (plumply) ovoid or lance-fusiform acute
0.1-0.3(-0.5) mm diam; pulvinules 0.5-2 mm; lfts obhquely oblong or ovate-ob­
long obtuse mucronulate or deltately apiculate (8-)12-36(-46) x 5-13(-16) mm,
2-3.7(-4.1) times as long as wide, at base deeply cordate on proximal and cuneate
on distal side, the margin plane, the blade veinless above, the midrib prominulous
beneath and commonly giving rise to 1-3 secondary veins palmately radiating
into the cordate base of blade and sometimes on the same or on both sides to
l-3(-4) weak pinnate ones, these expiring weU short of anastomosis.
Peduncles ascending 6-30 mm, all 1- or most (all) 2-3-fld, the raceme-axis
0-6(-8) mm; bracts resembhng stipules but only 1.5-4 mm; pedicels 3-9(-ll) mm;
fl-buds when young nodding subglobose pilosulous; sepals thinly herbaceous,
membranous where covered in bud, elliptic or obovate-elliptic obtuse, scarcely
graduated, the innermost (4-)4.5-6.5(-7) mm, all deciduous with the petals; petals
glabrous or externally puberulent at the claw, yellow drying whitish brownveined,
obovate-cuneate (5-)6-9(-l0) mm, sometimes not fully expanding but if
so lasting only one day; androecium glabrous, functionally 7-merous, the fertile
members accrescent toward the abaxial side of fl, the 2 next to the minute spat­
ulate staminodes shortest, their filament 1.1-1.8 mm, their anther 1.5-2 mm, the
2 latero-abaxial (oppositipetalous) longest, their filament 2.5-^ mm, their anther
(1.8-)2-2.8 mm, the 3 other intermediate, the anthers of all narrowly oblong
obtuse. Innately incurved 0.6-0.8 mm diam, dehiscent at apex by an obhquely
terminal pore, their walls thin-textured bicolored, castaneous along the connectival
grooves, yellow laterally and there only obscurely sulcate; ovary densely
white-pUosulous; style incurved from ovary (0.5-)0.7-1.4 mm, distally dilated
into a symmetrically or obUquely truncate membranous-margined stigmatic cavity
0.4-0.6 mm diam; ovules (22-)25-36.
Pod ascending or (from prostrate stems) humistrate, sessile or almost so, in
profile narrowly oblong to oblong-oblanceolate. Innately incurved or rarely
straight, abruptly contracted at apex into a short subulate beak, the strongly
turgid body 17-30 x 4.5-6.5 mm, the thin green puberulent and setulose valves
early dry brown and papery, differentiated into a central darker band low-cor­
rugate over the seeds and broad paler sutural margins, dehiscent downward
through both sutures, the interseminal septa broad membranous castaneous, the
whole dehisced pod long-persistent on the drying stems; seeds turned with broad
faces to the septa, stacked into 2 crowded files and often distorted by mutual
pressure, the perfect ones compressed-pyriform or paddle-shaped (2.2-)2.4-3.2
(-3.7) X 1.8-2.3(-3) mm, the testa brownish-ohvaceous becoming when fully ripe
gray or pinkish-gray and crackled, sinuously colhculate-rugulose overall, the
round or elliptic areole 0.35-0.5 x 0.25-0.4 mm.—CoUecrions: 53.
Stony hiUsides, plains, bajadas, gulUed bluffs along streams or dry washes,
sometimes prohficaUy colonial on roadsides, mostly in Larrea scrub, mesquital
or desert grassland at 500-1800 m, widespread over the n. Chihuahuan Desert
and around the margins ofthe Gila Basin in s.-e. Arizona, immediately adjoining
Sonora, s. New Mexico and trans-Pecos Texas s. to centr. Coahuila, extending