io6 



THE CACTACEAE. 



Illustrations: Cact. Journ. i: pi. for March; 181; Wiener 111. Gart. Zeit. 29: f. 22, 

 No. 4; Monatsschr. Kakteenk. 8: 131 ; 15: 73; Forster, Handb. Caet. ed. 2. 522. f. 65; 523. 

 f. 66; Cact. Mex. Bound, pi. 20; Median's Monthly 9: pi. 6; Mollers Deutsche Gart. Zeit. 

 25: 474. f. 6, No. 23; Schumann, Gesamtb. Kakteen f. 59; Schelle, Handb. Kakteenk. 158. 

 f. 87, as Echinocactus setispinus; Monatsschr. Kakteenk. 1: pi. 9; Gartenwelt 9: 266, as 

 Echinocactus cachetiamts; Mollers Deutsche Gart. Zeit. 25: 474. f. 6, No. 29, as Echinocactus 

 setispinus longispinus. 



Figures no and 111 show a flower and fruit copied from plate 20 of Cactaceae of 

 the Mexican Boundary; figures 112 and 113 are from photographs made by Robert 

 Runyon at Brownsville, Texas; figure 114 is from a photograph of a plant sent from 

 Brownsville by Robert Runyon. 



13. STROMBOCACTUS gen. nov. 



A low, depressed, nearly spineless cactus, with imbricated chartaceous scale-like tubercles; 

 flowers small, central, subcampanulate, nearly white; scales on the flower-tube with thin papery 

 margins; scales on the ovary only near the top, small; fruit nearly naked; seeds small. 



Type species: Mammillaria disciformis De Candolle. 

 One species is known, native of Mexico. 



The generic name is from arpoiifios top, and kclktos cactus, referring to the shape 

 of the plant. 



Figs. 115 and 116. Strombocactus disciformis. 



1. Strombocactus disciformis (De Candolle). 



Mammillaria disciformis De Candolle, Mem. Mus. Hist. Nat. Paris 17: 114. 182S. 



Echinocactus iurbiniformis Pfeiffer, Allg. Gartenz. 6: 275. 1838. 



Echinofossulocactus Iurbiniformis Lawrence in Loudon, Gard. Mag. 17: 318. 1841. 



Mammillaria turbinata Hooker in Curtis's Bot. Mag. 69: pi. 3984. 1843. 



Cactus disciformis Kuntze, Rev. Gen. PI. 1: 260. 1891. 



Cactus turbinatus Kuntze, Rev. Gen. PI. 1: 261. 1891. 



Anhalonium lurbiniforme Weber, Diet. Hort. Bois 90. 1893. 



Echinocactus disciformis Schumann in Engler and Prantl, Pflanzenfam. 3 6a : 189. 1894. 



Plants small, depressed, turbinate or semi-globose, 5 to 6 cm. broad; tubercles somewhat charta- 

 ceous, imbricate, more or less winged, bearing 1 to 4, white, acicular spines when young, naked when 

 old; young areoles with white wool, naked in age; flowers from center of plant, 2 cm. long or less; 

 scales and outer perianth-segments dark red, with whitish margins; inner perianth-segments white, 

 lanceolate, acute, spreading; filaments much shorter than the inner perianth-segments, purple; 

 stigma-lobes about 7, long, twisted; ovary naked except at the top, small; fruit 7 mm. long; seeds 

 3 mm. in diameter. 



Type locality: Mineral del Monte, Mexico. 

 Distribution: Central Mexico. 



