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

1982] CASSIINAE—SENNA 327
glabrous or strigulose, the style 1-2 mm, not dUated and only 0.2-0.3 mm diam
immediately beneath stigma; ovules (6-)8-14.
Pod (of vars. organensis and extratropica, otherwise unknown) spreading at
random angles or dechned, the stipe 1.5-4 mm, the oblong almost straight pianocompressed
body (3-)3.5-6.5 x 1.1-1.5(-1.7) cm, prominently margined by su­
tures, the purphsh-brown, finally papery valves scarcely raised over seeds, the
intraseminal septa very narrow, 4-5 mm apart; seeds oblong-obovate compressed
6-7.5 X 4^.5 mm, the testa atrocastaneous lustrous, a large shadowy spot but
not tmly differentiated areole on either face.
This neatly ornamental even though small-flowered senna resembles Andean
S. mandoni in foUage and pod but differs in the longer stipules and bracts, the
more abmptly tmncate anthers and especiaUy in the shorter style not hooked at
apex. Chilean S. cruckshanksii, although distantly allopatric in the coastal cor­
diUera of central ChUe, is too closely simUar to be other than a close genetic
relative which we can distinguish only by the narrower stipules and floral bracts
and a more slender style, weak and perhaps not specifically adequate characters.
For comment on two related sennas sympatric with S. organensis var. organensis
in Espirito Santo and Rio de Janeiro see our accounts of S. pneumatica and S.
itatiaiae. The habitally similar and partly sympatric S. (ser. Corymbosae) oblongifolia
is distinguished at anthesis by the infrafoholar petiolar gland of most leaves
and at least 32 (not 6-14) ovules, and later on by the narrower tumid pod and
unmarked seeds turned broadside to the septa.
The known populations of 5. organensis as defined in the foregoing description
are heteromorphic in number of leaf-stalk glands, in number, texture and venu­
lation ofthe leaflets, and sometimes further in proportion ofthe abaxial stamens,
but all retain a common facies, a characteristic perianth and, so far as known, a
characteristically short but broad, piano-compressed pod of papery texture. Two
variants emerge as clearly defined geographic varieties, a var. organensis in Rio
de Janeiro and adjoining Minas Gerais and Espirito Santo which is replaced on
Serra do Mar in Parana by var. extratropica. With these relatively well documented
entities we associate, under the provisional title of var. heterandra and
var. friburgensis, two peculiar sennas from within the range of var. organensis.
The pod of neither is known and their taxonomic status will require reappraisal
as and when new data permit.
Key to the Varieties of S. organensis
1. Filaments of 3 abaxial stamens 2-3 mm and their anthers ±3^ mm long; range of the
species.
2. Lfts 4-8 pairs; gland between proximal and some distal pairs of lfts; venulation of upper
face of lfts immersed or very faintly raised; ovary strigulose; Rio de Janeiro and adjacent
Minas Gerais-Espirito Santo. 104a. var. organensis (p. 328).
2. Lfts 3-5 pairs; gland between proximal pair only; venulation of both faces prominulous,
at least in mature blades; ovary glabrous; e. Parana. 104c. var. extratropica (p. 328).
1. Filaments of 2 or 3 abaxial stamens 4.5-5.5 mm, their anthers 5-7 mm long; local on Sas.
da Mantiqueira and dos Orgaos in Rio de Janeiro.
3. All 3 abaxial stamens elongate and subisomorphic, fertile; gland between proximal pair
of lfts only or between proximal and 1-2 penultimate pairs; lfts relatively thin-textured,
the distal pair oblanceolate ±10-13 mm wide; Sa. da Mantiqueira, especially on Mt.
Itatiaia. 104b. var. heterandra (p. 328).
3. Two antepetalous abaxial stamens elongate and fertile, the centric one between them
much smaller and sterile; glands between all but distal pair of lfts; lfts notably coriaceous,
the blade ofthe distal pair oblong-obovate 13-22 mm wide; Sa. dos Orgaos.
104d. var. friburgensis (p. 329).