2S6 PROCEEDINGS OF THE AMERICAN ACADEMY 



mostly 6 lines, lower ones 6-10 lines, upper ones 8-15 lines long; 

 central spine, if present, 12- 15 lines long. 



§ 3. Pentcdoplii. 



23. C. Berlandieri, E. in B. C. R. : humilis, perviridis ; caule dif- 

 fuso subtereti articulato ramosissimo ; tuberculis conicis 5 - 6-fariis ; 

 aculeis 6-8 setaceis brevibus radiantibus albidis, centrali sin^ulo 

 multo longiore fusco ; floribus magnis ; petalis angustis recurvatis ; 

 seminibus tuberculatis. 



On the Nueces, in Southern Texas : fl. May and June. — Stems 1^ 

 - 6 inches long, one inch thick ; radial spines 4-5 lines long, cen- 

 tral one 6-12 lines long, toward the base of the branches shorter. 

 Flower 2-4 inches lon^. 



o 



24. C. PROCUBIBENS, E. in PI. Lindh. 1850 : humilis, perviridis ; 

 caule diffuso subtereti 4- 5 angulato articulato ramosissimo; aculeis 

 4-6 radiantibus albidis, centrali nuUo vel singulo paullo longiore ob- 

 scuro ; floribus magnis ; petalis obovato-spathulatis patulis seu sub- 

 recurvis ; seminibus tenuissime verrucosis. 



On the Rio Grande, below Matamoras : fl. May and June. — 

 Similar to the last; but more slender, 6-8 lines in diameter; radial 

 spines 1-2 lines long, central one, if present, 2-3 lines long. Flower 

 above 3 inches long. 



§ 4. Graciles. 



25. C. TUBERosus, Poselger : e radice tuberosa tenuissimus, teres, 

 sursum incrassatus, demum articulatus, 8-costatus ; aculeis minutis 

 setaceis, 9-12 radiantibus, centrali singulo longiore sursum adpresso ; 

 flore subterminali ; seminibus minutis scrobiculatis. 



Between Laredo and Mier on the Rio Grande. Tuberous root J- - 

 1| inches thick. Stem above 4 - 8 lines thick; radial spines hardly 

 1 line, central ones 2-3 lines long. Seed smaller than in any other 

 Echinocereus, 0.4 line long, with the tubercles confluent. 



Subgen. 2. Eucereus. Caulis elongatus : fasciculi aculeorum ste- 

 riles et florigeri similes : floris tubus elongatus, sa^pissime aculeolis 

 capillaceis munitus : stigmata pallida : semina la^via seu raro ru- 

 gosa: embryo hamatus. 



26. C. Emoryi, E. in Sill. Journ. 1852 : prostratus ; ramis adscen- 

 dentibus 15-costatis ; areolis confertis ; aculeis setaceis rigidis flavis. 



