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

1982] CASSIINAE—SENNA 231
the hornotinous branchlets, lf-stalks and lower face of lfts aU densely pUosulous;
stipules essentiaUy of var. cana, (4-)6-l0 x (l-)2^ mm, at base auriculate-am­
plexicaul; glands usuaUy 0 at proximal and distal pairs, elsewhere stipitate; lfts
4-6 pairs, varying from eUiptic-oblanceolate to narrowly obovate, either obtusemucronulate
or deltately acute, 3-6.5 x 1.1-2.6 cm, 2.1-3 times as long as wide;
floral bracts 4-8 x 1.4-2.8 mm; fls relatively smaU, the long petal 16-20 mm; pod
unknown.—Collections: 4.
Habitat scarcely known, sometimes in caatinga thickets or about rock outcrops,
±300-700 (?) m, local in the valleys of Rios Pardo and Jequetinonha in s.-e. Bahia
and adjoining Minas Gerais, and in aberrant (possibly distinct) form in the vaUey
of Rio Doce in centr. Espirito Santo (Colatina); cultivated in Rio de Janeiro
(RB).—Fl. II-III.
This and the variety next following seem clearly distinct from var. cana in their
looser and longer pubescence of incumbent or sinuously ascending, not crisped
and matted hairs, but resemble it in all other respects. Their status is, however,
provisional, pending discovery ofthe pod. Our one collection from Espirito Santo
(Duarte 9010, M, NY) is notable for the presence of a gland between the proximal
pair of leaflets and for leaflets themselves rather broader and more nearly obovate
than usual in S. cana sens. lat. Its general habit somewhat suggests the coastal
S. australis, but the flower is much smaller and the fohage of thinner texture and
less prominently reticulate. Here again the pod may provide crucial evidence.
59d. Senna cana (Nees & Martius) Irwin & Barneby var. phyllostegia Irwin &
Barneby, var. nov., cum var. pilosula pube, cum var. cana caeteris
omnibus congruens, ab ambabus bracteis florahbus fohosis ovato-acuminatis
2.5-4 (nee lanceolatis 1-2.8) mm latis diversa.—BRAZIL. Bahia:
mata higrofila entre Itirugii e Maracas 23.1.1965 (fl), E. Pereira
9658 e G. Pabst 5547.—Holotypus, NY; isotypi, BRADE, M.
At anthesis 1.5-3 m; vesture of var. pilosula; stipules lance-caudat^, falcately
incurved to vertical, from point of attachment 4.5-10 mm long, at base variably
dilated and reflexed 0.7-2(-3) mm wide, when much dilated auriculate-amplexicaul;
glands at aU except proximal and distal pairs, stipitate; lfts (4-)5-7(-8)
pairs, the distal pair elliptic or lance-elliptic acute or obtuse (2.3-)2.5-
5 X (0.7-)0.9-1.5(-1.9) cm, 2.3-3.3(-3.8) times as long as wide; floral bracts
fohaceous ovate-acuminate (4-)6-12 x 2.5-4 mm, persistent into fuU anthesis;
longest petal 18-24 mm; pod unknown.—Collections: 7.
Disturbed woodland and rocky slopes along rivers, on sandstone or laterite,
400-1000 m, locaUy abundant on the sources of rios Paraguacu and de Contas in
Sa. do Sincora, and at one distant station on Rio Jequetinonha (Itaobim) in n.-e.
Minas Gerais.—Fl. I-IV.
This variety closely resembles the last at aU essential points, but differs in the
enlarged and apparently more persistent bracts which lend a distinctive aspect to
the flowering raceme. Contrary to a general rule, that bracts and stipules in
Cassieae tend to increase or wane together, the stipules of var. phyllostegia are
on the average less, not more dilated than those of var. pilosula. In Sa. do Sincora
var. phyllostegia is easUy distinguished from vicariant (perhaps marginaUy sym­
patric) vars. cana and hypoleuca by a combination of pilosulous vesture and
broad bracts. Its disjunct occurrence within the range of var. pilosula in north­
eastern Minas Gerais is difficult to explain. The starion lies on the main Brasilia-