Cassia caiapo 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

  • Scientific Name

    Cassia caiapo H.S.Irwin & Barneby

  • Type

    Holotypus, UB; isotypi, F, K, NY, RB, US.

  • Description

    Latin Diagnosis - Cassia caiapo Irwin & Barneby, sp. nov., C. lomatopodae notulis multis similis et certe affinis, ab ea imprimis petiolo communi ventraliter angustissime obtuse 2-costato (nec 2- alato) foliolisque (2-)3—4 (nec 1 — 3)-jugis ovatis (nec oblanceolato-obovatis) margine planis (nec revolutis), C. labouriaeae xylopodio robusto, foliolis subduplo majoribus (2.5-)3—5 (nec 1.5-2.2) cm longis, insuper ab ambabus adspectu toto abstans.

    Distribution and Ecology - Cerrado, near 1000 m, known only from the type-locality in Serra do Caiapo near the s.-w. corner of Goias. - Fl. XI-XII.

    Description - Amply leafy undershrub 5-10 dm, with few simple erect stems arising annually from a knotty xylopodium, the smooth glutinous stems, petioles and axes of inflorescence hispid with divaricate reddish setae up to ±5 mm, the stipules, lf-rachis, pulvinules, and margin of lfts in addition thinly villosulous with fine short eglandular hairs, otherwise in all parts glabrous, the foliage thin-textured, the lfts glutinously lustrous above, paler and duller beneath, coarsely open-reticuatle on both faces, the racemose inflorescence terminal, probably not or little exserted. Stipules erect, green, narrowly lance-attenuate, 3.5-6 mm, strongly 1-nerved, persistent. Lvs ascending, (6-)8-15 cm, petioled; pulvinus ovoid, moderately inflated, discolored, wrinkled when dry, 1.5-2.5 mm; petiole (2-)2.5-3.8 cm, 0.7-1.2 mm diam, shallowly and narrowly sulcate ventrally, not winged; rachis (1.5-)2.5-7 cm; lfts (2-)3-4 pairs, tilted forward and inclined face to face on dilated, when dry transversely wrinkled pulvinule 1.5-2.5 mm, either uniform in size or slightly decrescent upward, in outline asymmetrically ovate-elliptic, obtuse but mucronulate by the excurrent midrib, (2.5-)3-5 x (1.5-)1.7-2.7 cm, at base cordate on proximal and rounded on distal side, the ciliolate and forwardly setulose margin plane, entire or obscurely crenulate, the blades papery, olivaceous both sides but a little paler and duller beneath, the subcentric straight midrib and 5-9 pairs of major secondary nerves strongly and subequally elevated both sides, the tertiary and subsidiary venules also prominulous, forming an open, irregular reticulum of plane areoles mostly >-1 mm diam. Inflorescence terminal, racemosely many-fld, known only from budding specimens but probably not greatly elongating, in aspect resembling that of C. lomatopoda at the same stage of growth; bracts resembling stipules but a little shorter; buds ovoid, sharply apiculate, glabrous. — Collection: 1. Plate 14.

  • Discussion

    While only incompletely known from specimens in young flower-bud, C. caiapo is confidently described as a new species related to C. lomatopoda and C. labouriaeae, both of which it resembles in pubescence and texture of the foliage. It is perhaps closest to C. labouriaeae, known only from Sao Paulo, but differs in the presence of a stout xylopodium in place of a shallow, unmodified root, in the much larger leaflets, glabrous buds, and very probably in larger flowers. The oblanceolate to narrowly obovate leaflets of C. lomatopoda, subsessile on widely wing-margined leaf-stalks, are so different from the ovate-elliptic, petiolulate leaflets and unwinged leafstalk of C. caiapo that there can be no possibility of confusing the two. The type-locality of C. caiapo, on the headwaters of Rio Claro, a western affluent of Rio Paranaiba rising close to the Goias-Mato Grosso boundary, lies nearly 400 km distant northwestward from the nearest known station for C. lomatopoda.

    The epithet caiapo commemorates the Indian people inhabiting parts of Mato Grosso and Goias in pre-Columbian times.

  • Distribution

    Goiás Brazil South America| Brazil South America|