112 



THlv CACTACEAIv. 



4. Wilcoxia papillosa sp. n<v. 



Tap-root spindle-shaped, fleshy, 4 to 7 cm. long, 2 cm. in diameter, this giving off long fibrous 

 units; stems slriuk'r with few branches, 3 to 4 dm. long, perhaps longer, 3 105 mm. in diameter, 

 glabrous, but the whole surface covered with minute papillae ; ribs low, indistinct, perhaps 3 to 5; 

 auolrs small, distant, i to 3 cm. long, white-woolly; spines in clusters of 6 to 8, minute, yellowish 

 brown, bulbose at base, i to 3 mm. long; flowers scarlet, 4 to 5 cm. long; scales on the ovary and 

 lie iwer-tubc small, linear-cuspidate, the lower ones naked or nearly so, those at the top of the tube 

 with long white wool and several brown bristles (8 to 12 mm. long) in their axils; perianth-segments 

 2 cm. long; fruit probably spineless. 



Collected by C. A. Purpus at Culiacan, Sinaloa, Mexico, October i, 1904, and now 

 deposited in the Herbarium of the University of California (No. 160654), an d in the same 

 vState at Tinamaxtita, San Ignacio, altitude 1,340 meters, May 20, 1919, by a Mexican 

 Commission which was studying the natural resources of Sinaloa (No. 848). 



The plant is called cardoncillo. 



17. PENIOCEREUS (Berger) Britten and Rose, Contr. U. S. Nat. Herb. 12: 428. 1909. 



Plants low, slender, from an enormous, fleshy, turnip-shaped root ; stems and branches usually 

 4 or 5-angled, rarely 3 or 6-angled; spines of all the areoles similar; flowers very large for the size 

 of the plant, funnelform, nocturnal, white, the outer perianth-segments tinged with red; tube of 

 flower long, slender, with long hairs in the axils of the upper scales, but with clusters of spines on 

 the lower part as also on the ovary; fruit spin}', ovoid, long-pointed, bright scarlet, fleshy, and 

 edible; seeds black, rugose, with a large oblique hilum. 



A monotypic genus of the southwestern United States and northern Mexico. 



The generic name is from the Greek, signifying thread-cereus. 



1. Peniocereus greggii (Engelmann) Britton and Rose, Contr. U. S. Nat. Herb. 12: 428. 1909. 



Ccrcus greggii Engelmann in Wislizenus, Mem. Tour North. Mcx. 102. 1848. 

 Cereus poltsii Salm-Dyck, Cact. Hort. Dyck. 1849. 208. 1850. 

 Cereus greggii transmontanus Engelmann, Proc. Amer. Acad. 3: 287. 1856. 

 Cereus greggii cismontanus Engelmann, Proc. Amer. Acad. 3: 287. 1856. 

 Cereus greggii roseiflorus Kunze, Monatsschr. Kakteenk. 20: 172. 1910. 



Root often very large, sometimes 6 dm. in diameter, weighing 60 to 125 pounds, usually 15 

 to 20 cm. long by 5 to 8 cm. in diameter; stems 3 dm. to 3 meters high, 2 to 2.5 cm. in diameter, 

 the young parts pubescent; spines small, blackish; radials 6 to 9; central usually i, sometimes 2; 

 flower 15 to 20 cm. long, the tube slender and terminating in a short funnelform throat, covered with 

 stamens; inner perianth-segments lanceolate, acute, 4 cm. long, spreading, or the outer ones re- 

 flexed; filaments erect, exserted; style slender, the stigma- 

 lobes about i cm. long; fruit tuberculate, 12 to 15 cm. long, 

 including the elongated beak. 



Type locality: Near Chihuahua, Mexico. 

 Distribution: Western Texas, southern New Mexico 

 and Arizona to Sonora, Chihuahua, and Zacatecas. 



FIG. 167. Flower of Peniocereus greggii. Xo.5- 

 FIG. 168. Fruit of same. Xo.5- 



