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

1982] CASSIINAE—SENNA 127
biseriate seeds embedded, broadside to the septa, in thin slimy foerid pulp; seeds
ellipsoid or subreniform-ellipsoid 3.5-5.7 x 2-3 mm, the atrocastaneous lustrous
testa smooth or remotely pitted, exareolate.
The species described above as S. papillosa is the same for which Bentham
(1871) provisionaUy but mistakenly took up the name Cassia inaequilatera Balbis,
a species safely and certainly distinguished from all forms of S. fruticosa, S.
bacillaris, S. oxyphylla and S. dariensis by the long narrow pipelike, ultimately
dehiscent pod coarsely granular-papUlate overall and at the same time lacking
externally differentiated sutures. In kindred species with terete pod the valves,
except where venulose or remotely resinous-verruculose, are perfectly smooth
and at maturity often glossy, and the sutures form conspicuous bands down the
length of the dorsal and ventral faces, bands emphasized in S. bacillaris and S.
oxyphylla by thickened borders. The pod of S. fruticosa, which lacks such bor­
ders, is terete hke that of S. papillosa but at once much shorter and broader,
while that of S. dariensis, though equaUy long, is at once narrower and strongly
compressed laterally, with coarse salient sutures and seeds marshalled into a
single row. The seeds of S. papillosa differ from those of S. fruticosa and S.
bacillaris in their eUipsoid form and lack of areole, but except for the generally
narrower outUne are scarcely different from those of 5. oxyphylla.
While instantly recognized in the fruiting stage, S. papillosa at anthesis cannot,
as Bentham realized, be readUy distinguished from true S. bacillaris or, we must
add, from all forms of S. oxyphylla, S. fruticosa and S. dariensis, with each of
which it shares part of its range. The problem is aggravated by the fact that the
inflorescence, which may be either leafy-bracteate throughout or leafless and
exserted, and the individual flower, which varies considerably in length and amphtude
and lacks any distinctive feature in the androecium, both tend to resemble
in form those of the immediately sympatric relative: in Veracruz and Oaxaca S.
fruticosa; in middle Central America S. bacillaris and S. dariensis; in northern
South America S. oxyphylla. In practice we have identified as S. papillosa those
Mexican flowering specimens which appear to differ from sympatric S. fruticosa
by appressed leaf-pubescence and sharply short-acuminate leaflets together with
at least 140 (not ±80-100) ovules; and those large-flowered Central American
ones with proximal leaflets not very highly asymmetric and sepals relatively firm
and narrow as compared with S. bacillaris. But recognizing the Ukelihood of error
we have taken care to formulate the statement of range on evidence of fruiting
specimens alone. These estabhsh for S. papillosa a certain northern limit at Mi­
santla on the Gulf slope in Mexico near 20°N and a southern one on Sa. de Macarena
in trans-Andine Colombia at 3°N. The apparent absence of S. papillosa from
east-central Panama may be explained, perhaps, by a fortuitous lack of fruiting
material from the area.
At its southern hmit S. papillosa is represented by a series of populations
notable for many geminate racemes in the inflorescence, a tiny calyx, and exceptionally
short-pediceUed small flowers. This, already described as Chamae­
fistula angusta, deserves varietal status. The four Brittonian chamaefistulas listed
in the synonymy of var. papillosa were described without any diagnostic prog­
nosis of substance and can be dismissed without further ceremony.
Key to the Varieties of S. papillosa
1. Fls relatively ample, the longer (inner) sepals up to 5.5-10 mm, the longest petal (of truly
expanded fls) 12-23 mm; racemes usually solitary at each node of the inflorescence; range
ofthe species n.-ward from Venezuela and middle Magdalena valley in Colombia.
13a. var. papillosa (p. 128).