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

152 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 35
Senna ruiziana is the commonest cauliflorous member of ser. Bacillares in
western Amazonia, notable for flowers disproporrionately smaU for the ample
leaves, which bear behind the pulvinules of the distal pair of leaflets a glandularthickened
seta. The relarively short erect, falcately bent or almost annular, lat­
erally flattened pod containing well over one hundred seeds doubled up into two
rows on each side of a shaUowly intruded septum is unique, so far as known, in
the series. Groups of popularions situated to the north and south of laritude 13°S
have evolved into taxonomicaUy disrinct units.
Key to the Varieries of 5. ruiziana
1. Fls relatively ample, the petals when fully expanded (8-)9-11.5 mm; anthers 4-5.5(-6) mm;
Ecuador, extreme s.-e. Colombia, and trans-Andine Peru s. to Junin and the Mantaro valley
in Huancavelica (0-13°S). 25a. var. ruiziana (p. 152).
1. Fls small, the petals ±7 mm; anthers 2.8-4 mm, almost beakless; s.-e. Peru (Cuzco) and
Bolivia (lat. 13-17°S). 25b. var. micrandra (p. 152).
25a. Senna ruiziana (G. Don) Irwin & Barneby var. ruiziana. Chamaefistula rui­
ziana G. Don, 1832, I.e., sens, str.—"Native of GuiaquU [but doubtless
really from Peru, very probably from Huanuco], Cassia macrophylla,
Ruiz et Pav. in herb. Lamb[ert.]."—Holotypus, BM! isotypi, FI (hb.
Webb.), G, MA (hb. Pavon. 14130) = F Neg. 294101—Cassia ruiziana
(G. Don) Vogel, Syn. Gen. Cass. 40. 1837.
Cassia pallidifolia Macbride, Field Mus. Bot. 13 (Fl. Peru), part 3 (1): 176. 1943—"Junin:
chamayo Valley, Carlos Schunke 62, type."—Holotypus, collected X.1929 (fl), F!
Cassia ruiziana sensu Bentham, 1871, p. 520; Macbride, 1943, p. 180.
Characters as given in key.—Collections: 75.
Wet tropical forest, monte and secondary woodland, in high forest mostly along
streams, sometimes on cliffs, apparently not uncommon at ±450-1600 m on the
upper tributaries of the Amazon, from Rio Putumayo in Colombia s. through the
valleys of Rios Huallaga and Ucayali to Rios Perene, Ene and Mantaro in Junin
and n. Huancavelica, extending more rarely e. into the Hylaean lowlands, down
to ±300 m, on the Amazon as far as Leticia, Colombia (near 70°W), to be sought
in adjoining Amazonas, BrazU.—CoUected in fl almost throughout the year, most
often X-III.—Matarro.
25b. Senna ruiziana (G. Don) var. micrandra Irwin & Barneby, var. nov., a var.
ruiziana floribus minimis, petalis ±7 mm, antheris suberostribus 2.8^
(nee 4-6) mm tantum longis, necnon distributione australi abstans.—
BOLIVIA: Yungas, anno 1890, Miguel Bang 464.—Holotypus, NY;
isotypi, F, K, M, MICH, MO, NY, US.—Ibid, anno 1885, H. H.
Rusby 5i7.—Paratypi, MICH, NY (2 sheets), US!
Characters as given in key and diagnosis.—CoUecrions: 2.
Wooded hillsides and river banks in the monte formarion, 700-1800 m, e. foot­
hUls of the Andes drained by Rios Madre de Dios and Beni in lat. 13-17°S, from
Cordillera de Carabaya in Cuzco (prov. Paucartambo and Quispicanchis), Peru
to Las Yungas in La Paz, Bolivia.—Fl. (in Peru) II-III.
The two Bohvian coUecrions on which we base var. micrandra were identified
by Rusby (in herb.) as Cassia affinis Benth., an obvious mistake corrected in
manuscript by Britton, who proposed to describe them as a new species of Cha­
maefistula, using the epithet boliviensis under which duphcates may possibly still
be filed in some herbaria. The plant is clearly very close to genuine S. ruiziana