918 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



stouter, brown ; flowers dark crimson, 10 cm. long, 7.5 cm. broad or more ; flower 

 tube 3 cm. long or more; perianth segments in 3 series, the series well sepa- 

 rated ; inner perianth segments oblong, 10 mm. broad, acuminate ; stamens red, 

 erect, exserted. 



4. Aporocactus conzattii Britt. & Rose, Cactaceae 2: 220. 1920. 

 Type from Cerro San Felipe, Oaxaca. 



Creeping, clambering, or hanging from a support, developing aerial roots here 

 and there ; stems 12 to 25 mm. in diameter ; ribs 8 to 10, rather prominent, low- 

 tuberculate ; areoles 3 to 4 mm. apart ; spines 15 to 20, acicular, light brown, 

 unequal, the longest 12 mm. long; buds nearly erect, covered with brown aci- 

 cular spines or bristles; flowers 8 to 9 cm. long; tube nearly straight, red, 

 bearing a few ovate scales, their axils short-woolly and with a few bristle-like 

 spines ; upper inner perianth segments arching forward, the lower ones some- 

 what reflexed, all narrow, 6 to 7 mm. broad, acute, brick-red ; tube proper 2 

 to 2.5 cm. long; throat about 1 cm. long, narrow, bearing stamens all over its 

 surface. 



5. Aporocactus martianus (Zucc.) Britt. & Rose, Cactaceae 2: 220. 1920. 

 Cere us martianus Zucc. Flora 152: Beibl. 66. 1832. 



Eriocereus martianus Riccobono, Boll. Ort. Bot. Palermo 8: 240. 1909. 



Central Mexico. 



Stems rather stout, somewhat branched, 15 to 18 mm. in diameter; rib& 

 about 8, low, obtuse ; areoles 12 mm. apart ; spines 6 to 8, acicular to bristle- 

 like; flowers a deep rose, 8 to 10 cm. long; outer perianth segments narrowly 

 lanceolate, acuminate ; perianth segments similar but long-acuminate ; fruit 

 globular, 2 cm. in diameter, greenish, spiny. 



25. ECHINOCEREXTS Engelm. in Wisliz. Mem. North. Mex. 91. 1848. 



Plants always low, perennial, erect or prostrate, sometimes pendent over 

 rocks and cliffs, single or cespitose, globular to cylindric, prostrate or pendent 

 if elongate ; spines of flowering and sterile areoles similar ; flowers usually 

 large, in some species small, diui'nal, in some not closing at night ; perianth 

 campanulate to short-funnelform, scarlet, crimson, purple, or rarely yellow, the 

 tube and ovary always spiny ; stigma lobes always green ; fruit more or less 

 colored, thin-skinned, spiny, the spines easily detached when mature; seeds 

 black, tuberculate. 



Besides the species listed here, several others occur in the southwestern 

 United States. The fruit of most of the species is edible and often of superior 

 quality. 



Flowers small, 1.2 cm. long or less 45. E. barthelowanus. 



Flowers large, usually conspicuous, rarely only 2 to 3 cm. long. 



Stems covered with long weak bristles or hairs 1. E. delaetii. 



Stems covered with spines, or rarely spineless. 



Flowers scarlet to salmon-colored, opening once but lasting for several days. 

 Stems usually weak, often trailing or at least becoming prostrate; rib» 

 nearly continuous. 



Flowers rosy red 2. E. scheeri. 



Flowers orange-red to salmon-colored. 



Flowers 8 to 11 cm. long ; wool from areoles on flower tube long. 

 Flowers 8 to 10 cm. long ; radial spines 9 or fewer. 



3. E. salm-dyckianus» 



Flowers 11 cm. long ; radial spines 10 to 12 4. E. huitcholensis. 



Flowers 6 cm. long or less; wool from areoles on flowers shorter 

 than the subtending scales 5. E. pensilis^ 



