Basic Literatur

Fig. 35. Sedum cuspidatum sp. nov. x 0.4

A New Sedum from Chiapas

By E. J. ALEXANDER

Among the contributions of Mr. T. MacDougall in past years to the succulent collections of the New York Botanical Garden, there have been several shrubby species of Sedum. The majority of these have been in the yellow-flowered group centering around S. dendroideum, but two of them have given evidence of being relatives of S. Adolphii. One of these has finally been coaxed into flower and proves to be an undescribed species of great interest. Its general habit is that of S. Adolphii, but it lacks the coarse heaviness of that species, its leaves being smaller, thinner, and more abruptly pointed, and the inflorescence is a more tightly compact, fewer flowered cyme, with the white flowers nearly sessile and more cupped at the base. For this plant, so outstanding in its habit, inflorescence and leaf-form, the following name is proposed:

Sedum cuspidatum Alexander, sp. nov.

Subgenus Pachysedum (Berger) Clausen

Planta frutex succulenta, in partibus omnibus glabra; caulibus 4-5 mm. crassibus; foliis alternis 2-2.2 crn. longis et 1 cm. latis et 3 mm. crassis, spatulato-cuspidatis, carinatis in latis inferioribus et superioribus; inflorescentia cymosa compacta, pedunculis 7 cm. longis, cum bracteis ellipso-lanceolatis 7 mm. longis; floribus albis, pedicellis 1 mm. longis; sepalis 3.5-5 mm. longis, oblanceolatis, acutiusculis, petalis 7 mm. longis, lanceolatis, acutis, canaliculatis, erectis ad mediis, deinde patulis; staminibus 6 mm. longis; antheris rubro-brunneis; squamis obovatis 0.8 mm. longis, 0.7 mm. latis, concavis, apice lunato-truncatis, carpellis erectis, 6 mm. longis.

Fig. 36. Sedum cuspidatum sp. nov. x 1.3

Plant glabrous in all parts, with fleshy, suffruticose stems 3-5 mm. thick, with many erect branches which become decumbent in age. Stems to 25 cm. long with pale gray-brown smooth skin. Leaves light yellow-green, glaucous towards the base, narrowly obovate, about 2 cm. long, 1 cm. broad, and 3 mm. thick, abruptly tapered to a blunt cuspidate apex, strongly keeled on the lower face and less strongly keeled on the upper face. Inflorescence lateral, the peduncle 7 cm. long, naked for the lower 1.5 cm., thence with erect, narrowly elliptic, obtuse bracts 7 mm. long. Flowers 12 mm. in diameter, borne in a tight, compact cyme, the pedicels barely 1 mm. long. Sepals unequal, 3.5-5 mm. long, oblanceolate, acutish. Petals white, 7 mm. long, erect for 3 mm., the remaining 4 mm. spreading, deeply channelled, acute and apiculate-hooded at the apex. Filaments 6 mm. long, white, slender-subulate, anthers purplish-brown, 0.5 mm. in diameter. Nectarean scales obovate, 0.8 mm. high, whitish, truncate-lunate at the pale yellowish apex, 0.7 mm. in diameter. Group of carpels 3 mm. in diameter; individual carpels greenish-white, erect, united for 0.8 mm. above the base, 6 mm. long, the body and style of equal length; styles pale green, stigmas minutely papillate.

Type collected near Ocozocoautla, Chiapas, Mexico, in the winter of 1942-43 and flowered at the New York Botanical Garden in February, 1946.