Cassia cytisoides var. brachystachya (Benth.) 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 cytisoides var. brachystachya (Benth.) H.S.Irwin & Barneby

  • Type

    Lectoholotypus, Riedel 566, K (hb. Benth.) = NY Neg. 1485 (plant at right)! isotypus LE! paratypi, Riedel 136, K (hb. Benth.), LE, in each case mounted with no. 566. Ample specimens collected by Riedel at Tejuco (Diamantina) in Dec. 1824 which appear iden

  • Synonyms

    Cassia brachystachya Benth.

  • Description

    Species Description - Either glabrous throughout or the young branchlets and associated If-stalks densely minutely pilosulous, the stipules, bracts, and sepals often thinly ciliolate; Ivs (2-) 2.5-5.5 cm, sessile; rachis (5-) 7-25 cm; Ifts of all or almost all Ivs 2 pairs, exceptionally 3 pairs, the proximal pair suborbicular-reniform, 13-35 x 12-36 mm, the terminal pair obliquely obovate- suborbicular, 13-35 x 9-40 mm; sepals 7.5-10 mm; petals very unequal, the four plane ones 12.5-19 x 8-11 mm, the falcate coiled one 21-25 x 6-9 mm. — Collections: 13.

    Distribution and Ecology - Thin sandy soil about outcrops in cerrado between 900 and 1100 m in the n.-centr. segment of Serra do Espinhaco between Diamantina and Grao Mogol, Minas Gerais, and descending disjunctly to restinga and thickets of the coastal woodlands of s. and centr. Bahia, from the mouth of Rio Jequitinonha to Salvador. — Fl. VIII-XII.

  • Discussion

     

    As defined above, var. brachystachya probably embraces two distinct geographic races, one native to the crest of Serra do Espinhaco above 900 m, the other to the Atlantic lowlands, where it occurs in restinga inland and reaches the dunes and sandy thickets along the shore. The available material from the lowland habitats is extremely sparse, but seems to differ from the upland, nomenclaturally typical form, in its somewhat larger leaves and leaflets, and especially in the more densely pilosulous young branchlets and leaf-stalks. But among three collections made at the same place 32 km inland from mouth of Rio Pardo (Belem 1674, 1704, 1721) there are glabrous individual plants, while some individuals from the highlands of Minas are incipiently puberulent. It might be expected that the plants of coastal Bahia would have more in common with the var. unijuga, likewise coastal but further north in Pernambuco and Alagoas, than with typical var. brachystachya, but var. unijuga is immediately separable by the single pair of leaflets raised on a developed petiole. Irwin (1964, p. 73, 89, figs 345, 349) has demonstrated in sect. Xerocalyx the existence of closely related, maritime and upland planalto races of the same species (Cassia ramosa Vog., C. tetraphylla Desv.)

  • Distribution

    Bahia Brazil South America|