13.07.2013 Views

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

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

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

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

1982] CASSIINAE—SENNA 343<br />

Dry rocky hUlsides, banks of ravines, sometimes colonial along watercourses<br />

in alluvial gravels, ascending into the puno formation, 2200-3900 m, locaUy plen­<br />

tiful on the w. slope of the Andes in s. Peru (Arequipa, presumably also Moque-<br />

qua and Tacna) and adjoining ChUe (n. Tarapaca).—Fl. irregularly through the<br />

year.<br />

The var. arequipensis is distinguished technicaUy from other varieties of S.<br />

birostris by the gray pUosulous vesture ofthe leaflets, which are at the same time<br />

relatively small, thick-textured, apparently veinless exce<strong>pt</strong> for the dorsally prom­<br />

inulous midrib, and borne on short pulvinules (0.3-0.8, rarely-1 mm), often ap­<br />

pearing sessile against the rachis. It is obviously very closely related to the glabrate<br />

and less xeromorphic var. birostris, vicariant northward, mostly at lower<br />

elevations, along the Peruvian coast as far as La Libertad. This has a calyx of<br />

essentially the same size and proportions, the same long-stalked abaxial anthers,<br />

and the same (nearly always) broad and (always) long-stipitate pod; but green,<br />

thin-textured leaflets visibly penniveined dorsally. The also simUar var. helveola<br />

ofthe central Peruvian Andes has, with the same pod and androecium, ventrally<br />

glabrous, dorsally penniveined leaflets and strongly graduated sepals hairy on the<br />

back. The type-collection of Cassia tarapacana agrees in every detaU with some<br />

flowering specimens of var. arequipensis from Arequipa.<br />

llOe. Senna birostris (Vogel) var. helveola (Macbride) Irwin & Barneby, stat.<br />

nov. Cassia helveola Macbride, Field Mus., Bot. 8(2): 91. 1930.—<br />

"Peru: Yanahuanca, De<strong>pt</strong>. of Huanuco [really De<strong>pt</strong>. of Pasco, prov.<br />

Daniel Carrion], June 16-22, 1922, Macbride & Featherstone 1183<br />

. . ."—Holotypus, F! = F Neg. 53096; of 2 paratypi cited, Macbride<br />

& Featherstone 2526 is conspecific, but Weberbauer 7608 = var.<br />

huancavensis.<br />

Cassia helveola sensu Macbride, Field Mus., Bot. 13, <strong>pt</strong>. 2(1): 167. 1943, var. exclus.<br />

Shrubs 1.5-3 m, the young branchlets, h-stalks and inflorescence densely pi­<br />

losulous or loosely strigulose with sordid or lutescent hairs to 0.2-0.45(-0.6)<br />

mm, even the fl-buds silky-pUosulous and the young pod puberulent; stipules<br />

4-6.5 X 0.8-1.5 mm, densely pubescent dorsaUy; lvs (5-)6-13 cm; lfts<br />

(9-)10-14(-16) pairs, ovate-oblong to narrowly oblong-elli<strong>pt</strong>ic, the longest<br />

13-26 X 5-8 mm, (1.9-)2-3.6 times as long as wide, glabrous ventraUy, densely<br />

pUosulous dorsally, the venation as in var. birostris; racemes (7-)9-<strong>35</strong>-fld, corym­<br />

biform at anthesis; sepals pUosulous dorsaUy exce<strong>pt</strong> toward margins, strongly<br />

graduated, the outer 3.5-5 mm, the inner 7.5-10.5 mm; petals 11.5-16 mm; fila­<br />

ments of 2 long abaxial stamens 5-8 mm, the anthers as in var. birostris; ovary<br />

densely pUosulous; style 1.8-2.3 mm; stipe of (little known) pod ±5-7 mm, the<br />

broadly hnear body ±9x1 cm.—Collections: 12.<br />

Rocky and brushy hiUsides, river banks and gravels, sometimes on roadside<br />

cuttings, 2300-3250 m, locally plentiful in the Andes of n.-centr. Peru, from the<br />

sources of Rio Huallaga in Pasco and Huanuco n.-e., high on Pacific slope,<br />

through Ancash into La Libertad (Otusco).—Fl. I-IV.<br />

Comments on the close relationship within its species and on differential char­<br />

acters of var. helveola wiU be found under the vicariant vars. arequipensis and<br />

birostris. Care must be taken to distinguish h from sympatric and superficiaUy<br />

simUar S. versicolor, different at anthesis in having leaflets paler or brighter green<br />

above than beneath (contrary to the rule in Senna), in the broader (mostly 1.5-6,<br />

not 0.8-1.5 mm), more persistent stipules and in the slightly longer (11.5-16, not

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!