Monographs Details: Cassia belemii H.S.Irwin & Barneby
Authors:Howard S. Irwin, Rupert C. Barneby
Authority: Irwin, Howard S. & Barneby, Rupert C. 1978. Monographic studies in Cassia (Leguminosae, Caesalpinioideae). III. Sections Absus and Grimaldia. Mem. New York Bot. Gard. 30: 1-300.
Family:Caesalpiniaceae
Description:Latin Diagnosis - Cassia belemii Irwin & Barneby, sp. nov., inter C. salvatoris et C. zygophylloidem quasi intermedia, illius ramulorum annotinorum epidermi pallido exfolianti totoque habitu simillima sed foliis dimidio minoribus 2-4 (nec 4-7) cm foliolisque parvulis obovatis 5-21 (nec 15-45) mm longis, venulis secundariis 4-5-jugis (nec 7- 10-jugis tunc intricatim reticulatis) distinguenda, a C. zygophylloideae varietatibus brasiliensibus ramulorum epidermi pallida ac corolla majuscula (petalis majoribus ± 14-18 nec 8-12 mm longis) ut videtur distantior.

Species Description - Stiffly branched shrubs 2-3 m, with the old bark, exfoliating pallid epidermis of young shoots, stipules, and inflorescence as in C. salvatoris but the lvs shorter and the lfts smaller, subconcolorous and simply venose, except for the either finely pilosulous or sub- glabrous faces of the lfts shortly viscid-setulose and villosulous throughout. Lvs divaricate and widely ascending (1.5-)2-4 cm; petiole 10-19(-23) mm, a little longer or shorter than the first pair of lfts; rachis 1.5-6 mm; lfts obovate, obtuse or emarginate, (5-)8-21 x 4-14 mm, the blades chartaceous, brownish-olivaceous dull, on both faces either glabrous except for a tuft of hairs in the distal basal angle of midrib beneath or on both faces finely pilosulous, the plane margins villosulous-ciliolate or minutely ciliolate, the slender midrib and 4-5 pairs of major secondary nerves prominulous on both faces but only faintly raised above, the tertiary and subsequent venules either fully immersed and imperceptible or immersed and discolored, visible but not raised. Racemes mostly simple, rarely weakly branched, 7-30-fld, the axis 1.5-6 cm; pedicels 15-22 mm, bracteolate either above or below middle; buds subglobose, either minutely pilosulous or densely villosulous and setulose; fl in form, size, and proportion of parts almost that of C. salvatoris, the sepals ±7 x 2.8-3.5 mm, the largest of the four plane petals 14-17 mm, the coiled petal 15-18 mm; ovary either densely setulose or merely ciliate along the sutures; ovules 6-8. Pod (little known) ±4 x 0.7 cm, the valves reddish-brown, glutinous; seeds unknown. Plate 24.

Discussion:

A critical species, still poorly known or understood but obviously related to C. salvatoris, which is similar in habit and probably in habitat but distinguished by the much smaller leaves and simply venulose, not elaborately reticulate leaflets crowded toward the tip of the proportionately longer petiole. In both these species, as in the less closely related C. barbata found at greater elevations inland in Bahia, the epidermis of the current year's fertile branchlets early becomes pallid and peels off in flakes or ribbons, leaving the old trunks uniformly brown or blackish. It is otherwise with C. zygophylloides, of which the Brazilian varieties, although smaller-flowered and also confined to the interior highlands, much resemble C. belemii in foliage and habit; here the brown epidermis of the year's branchlets separates along fissures to expose a pale interior, the contrast in color being perpetuated as stripes, alternately light and dark on the old wood.

The first known collection of C. belemii sens, lat., collected by Blanchet before 1840, was misidentified by Bentham (1871, p. 583) as C. viscosa. The foliage is indeed highly suggestive of some forms of C. viscosa but C. belemii is evidently a stiffly branched shrub, described by Blanchet as a span and by Belem as 3 meters tall, therefore quite different in habit, and distinguished technically by the characteristic young bark just mentioned. No other cassia exactly similar has been seen, but a modern collection from the lower ParaguaƧu valley inland from Bahia Todos os Santos seems too closely related, in spite of some striking small differences, to be separated specifically. We regard these collectively as aspects of the species C. belemii, but separable at varietal level.

1. Rachis between the 2 pairs of lfts 3-6 mm; faces of lfts and pods glabrous or almost so, the lfts setulose-ciliolate; pedicels bracteolate much below the middle, 8-12 mm below calyx; buds thinly pilosulous at base, thence subglabrous; tertiary venulation of lfts immersed but highly discolored.

146a. var. belemii

1. Rachis between the pairs of lfts 1.5-2.5 mm; faces of lfts and pods finely villosulous overall, the lfts villosulous-ciliolate; pedicels bracteolate above middle, 1-6 mm below calyx; buds densely setulose and pilosulous to apex; tertiary venulation of lfts immersed and imperceptible.

146b. var. paludicola

 

Narratives:Cassia belemii