974 CONTRIBUTIONS FROM THE NATIONAL HEEBAEIUM. 



but forming a definite ring at the top of tlie tliroat ; style slender ; stigma 

 lobes linear ; ovary exserted, naked ; fruit smooth, greenish, purplish, or red, 

 globose, ellipsoid or short-oblong; seeds black. 



Only three species are known. 



Spines glabrous, even when very young 1. D. sphaerica. 



Spines puberulent. 



Tubercles very long (up to 5 cm.), pale green, glaucous; radial spines 6 to 

 12 ; central spines usually present 2. D. longim^amma. 



Tubercles much shorter, bright green ; radial spines 3 or 4 ; central spines 

 none 3. D. uberiformis. 



1. Dolichothele sphaerica (Dietr.) Britt. & Rose, Cactaceae 4: 61. 1928. 

 MammiUaria sphaerica Dietr.; Poselg. Allg. Gartenz. 21: 94. 1853. 

 Northern Mexico. Texas, the type from Corpus Christi. 



Low and depressed, often growing in large cespitose masses 20 cm. in 

 diameter, with a large thickened root; tubercles soft and turgid, resembling 

 those of the following species but shorter, 12 to 16 mm. long; areoles small, 

 circular, at first short-lanate ; spines 12 to 15, glabrous, generally pale yellow, 

 a little darker at ba.se at first, in age darker, often reddish, 7 to 9 mm. long, 

 spreading or a little curved backward ; central spine 1, straight ; flowers ap- 

 pearing toward the top of the plant but not from the axils of the younger 

 tubercles, with a rotate limb 6 to 7 (?) cm. broad; inner perianth segments 

 widely spreading, oblanceolate, acute to apiculate, tapering at base into a 

 slender claw ; fruit greenish white to purplish, short-oblong, 10 to 15 mm. long, 

 juicy, very fragrant ; seeds black. 



2. Dolichothele long-imamma (DC.) Britt. & Rose, Cactaceae 4: 62. 1923. 

 MammiUaria longimamma DC. Mem. Mus. Hist. Nat. 17: 113. 1828. 

 MammiUaria melaleuca Karw. ; Salm-Dyck, Cact. Hort. Dyck. 1849. 108. 1850. 

 MammiUaria gloJjosa Link. Allg. Gartenz. 25: 240. 1857. 



Tamaulipas and central Mexico. 



Solitary or cespitose, about 10 cm. high ; tubercles elongated, 5 cm. long, 

 somewhat glaucous, their axils hairy or naked ; spine areoles with white hairs 

 when young, in age naked ; radial spines 5 to 12, widely spreading, acicular, 

 2.5 mm. long, white to pale yellow, swollen and darker at base, puberulent; 

 central spines 1 to 3, usually solitary, porrect, similar to the radials but usually 

 darker with a blackish tip ; flowers citron-yellow, 4 to 6 cm. long. 



3. Dolichothele uberiformis (Zucc.) Britt. & Rose, Cactaceae 4: 63. 1923. 

 MammiUaria uheriforyyiis Zucc; Pfeiff. Enum. Cact. 23. 1837. 

 MammiUaria laeta Riimpler ; Forst. Handb. Cact. ed. 2. 247. 1885. 

 Central Mexico, the type fi'om Pachuca, Hidalgo. 



Globose, about 7.5 cm. high and 10 cm. in diameter; tubercles elongate, 2.5 

 to 3 cm. long, 12 to 15 mm. in diameter, dull green, shining, their axils naked ; 

 spine areoles nearly naked ; spines 3 or 4, all radial, puberulent, horn-colored 

 to reddish, nearly equal ; flowers yellow, 3 cm. broad ; outer perianth segments 

 reddish, the inner in 2 series, oblong, acute. 



49. SOLISIA Britt. & Rose, Cactaceae 4: 64. 1923. 



The genus consists of a single species. It was named for Don Octavio Soils, 

 of Mexico City. 



1. Solisia pectinata (Stein) Britt. & Rose, Cactaceae 4: 64. 1923. 

 PelecypJwra pectinata Stein, Gartenflora 34: 25 1885. 

 MammUlaria pectinifera Weber, Diet. Hort. Bois 804. 1898. 

 Puebla. 



