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

1982] CASSIINAE—SENNA 285
like that of S. roemeriana, 23-35 x 4-6 mm, hispid with stiffly ascending setae
0.7-1.2 mm; seeds biseriate, often deformed by crowding, when perfect compressed-pyriform
or paddle-shaped 2.3-2.7 x 1.6-2.2 mm, the moderately or
highly lustrous brown or brown-ohvaceous testa irregularly coarsely folded but
not rugulose-coUiculate, the round or broadly elliptic areole 0.3-0.4 mm diam.—
CoUections: 12.
GraveUy clay flats and stony hiUsides in microphyUous matorral, desert shrub
and desert grassland communities ofthe Mexican Plateau, sometimes colonial on
roadsides, mostly on hmestone or gypsum, 900-2300 m, extreme s.-e. Coahuila
s. through San Luis Potosi and adjoining Zacatecas to the Moctezuma valley in
n. Hidalgo (Ixmiquilpan), except in the latter state entirely within the s. lobe of
the Chihuahuan Desert.—Fl. (V-)VI-IX.
Senna mensicola is closely related to S. bauhinioides and S. roemeriana. Prior
to its description it had been confused with S. bauhinioides, but differs in the
larger flower and the cyhndric, not dilated and funnelform style. From S. roemeriana,
similar in corolla and gynoecium, it differs in generaUy lower stature,
relatively broad blunt leaflets about 2.5-3.5, not 4-8 times as long as wide and
a loosely hispid rather than appressed-strigose pod. The seeds of S. roemeriana
and S. bauhinioides are similarly sinuous-rugulose overall, whereas those of S.
mensicola are smooth. The androecia of S. bauhinioides and S. roemeriana are
ahke in that the fertUe stamens are strongly accrescent toward the abaxial side
of the flower, the two latero-abaxial being longest of all; in S. mensicola this
asymmetry is less emphatic and sometimes barely perceptible. The discrete range
of S. mensicola, lying southward from latitude 25°S, is further distinctive.
86. Senna ripleyana (Irwin & Barneby) Irwin & Barneby, Phytologia 44(7): 500.
1979 (lapsu ''riplevi^'). Cassia ripleyana Irwin & Barneby, Sida 6(1):
13, fig. 1. 1975.—"MEXICO. Chihuahua: ... 18 km w. of Jimenez
. . . 2.x. 1965 (fr), H. D. Ripley & R. C. Barneby 13,904.''—Holoty­
pus, NY!
Cassia ripleyi Irwin & Barneby ex Isely, Mem. N.Y. Bot. Gard. 25: 226. 1975, nom. nud.
Dwarf, loosely cespitose subacaulescent and shortly caulescent perennial herbs
from woody taproot and ultimately a branched caudex, including the exserted
peduncles 4-14 cm, pUosulous throughout with coarser, antrorsely incurved-as­
cending hairs less than 1 mm and a few weak spreading filiform ones up to ±2-2.5
mm, the 1 pair of lfts ashen beneath, greener above, pubescent on both faces,
the l(-2)-fld axiUary racemes exserted from the tufted fohage.
Stipules erect often recurved at tip, narrowly hnear-caudate (4-)6-10 mm,
strongly 1-nerved, persistent.
Lvs 1-5 cm; periole stiff l-2.5(-3.2) cm, at middle 0.4-0.5 mm diam, ribbed
dorsaUy, the ventral groove almost closed; petiolar gland divaricate from between
the 2 lfts, stipitate, in profile 0.7-2.7 mm, the slenderly lance-fusiform acute head
0.1-0.2 mm diam; lfts oblong- or obhquely obovate-elliptic obtuse mucronulate
or subapiculate (6-)8-20 x 3-10 mm, at base broadly cordate on proximal and
cuneate on distal side, the margin plane, the slender midrib prominulous beneath,
the blades otherwise veinless.
Peduncles stiffly erect or in fruit dechned, 2.5-6 cm, 1-, rarely 2-fld; bracts
lanceolate or triangular-subulate 1-2.5 mm, early dry deciduous; mature pedicels
5-10 mm; fl-buds nodding, obovoid pUosulous; sepals of subequal length 5-6.5
mm, the outer elliptic-oblanceolate the inner obovate, aU membranous-margined;