679 



must be touched with clean hands and 

 only by people who are well baptized, for 

 he is a good Christian, say the Christian 

 Tarahumaris, and keeps a sharp eye upon 

 the people around him'." 

 MAMMILLARIA SETI3PINA E. 



"Cactus setispinus: fasciculate and as- 

 cending, simple or branched at base, the 

 stems about 30 cm high and 3-6 cm in di- 

 ameter, densely covered with remarkably 

 long stout spines: tubercles short and 

 broadly conical, with axillary wool: 

 spines white, with black tips; radials 10- 

 12, wideiy spreading, very unequal, 10-34 

 mm long, slender and nexuous; central 

 spines 1-4, more rigid and much longer 

 (20-50mm), the upper ones straight, the 

 lowest one longest and hooked (.usually 

 upwards) and often variously curved and 

 twisted: fruit obovate and scarlet, 30 mm 

 long: seeds black and pitted. Type, Gabb 

 15 in Herb. Mo. Bot. Gard. Rocky 9r 

 gravelly soil, San Julio canyon, and in 

 the vicinity of San Borgia, Lower Cali- 

 fornia." Coulter Cont U S Nat Hb 3: 106 

 (10 Je 1894). 

 MAMMILLARIA THORNBERI Orcutt. 



Cylindrical, 1% inch in diameter, usually 

 2-3 inches high, erect, with 8 or 9 spiral 

 rows of tubercles, axils naked; 13-18 slen- 

 der white or brown tipped radials 14 inch 

 long; usually 1 slender flexuous hooked 

 central one-fourth to three-fourths of an 

 inch long, tipped with brown; fruit cla- 

 vate. scarlet, containing minute black 

 seeds. Tips of tubercles olive green, base 

 and axiTs and sunken portion of plant 

 tinged with purple; radials usually 13, the 

 upper sometimes the longest, often brown 

 nearly to the base; central occasionally 

 brown, usually the lower half white or 

 yellowish, often hooked upward, but often 

 twisted and turning in every direction. 

 Plant proliferous at I ase, forming numer- 

 ous offsets in the axils of tho buried or 

 lower tubercles; these quickly take root 

 and usually soon sever connection with 

 the parent, thus forming dense compact 

 masses of old and young .plants, upually 

 10-50 but in one, perhaps not exceptional 

 rase, T counted 110 distinct plants, in a 

 cluster all apparently originating from 

 the tallest individual in the group. Occa- 

 sionally a plant, from injuries sustained, 

 becomes bifurcate or forms a number of 

 aerial heads which remain permanently 

 attached but which usually form roots 

 of their own and eventually survive the 

 death of the parent. More than 1 central 

 spine appears very rare, but 2 or three 

 sometimes appear from the same small 

 woolly areola, one or all hooked, of equal 

 or varying length. The largest plant 

 among over 1,000 was V/ 2 inch in diameter 

 and nearly a foot high! Type, Orcutt, No. 

 2583: Arizona. Curiously the same plant 

 was found a few days earlier than by the 

 author by Prof. J. J. Thornber, and 

 planted in the cactus garden of the Uni- 

 versity of Arizona, and this interesting 

 addition to the cactus flora of the United 

 States may therefore appropriately bear 

 his name. 

 MAMMILLARIA TRICHACANTHA. 



A remarkable species on account of 

 its having hairy spines, introduced from 



680 



Mexico by F. de Laet (MfK 1904, 45, f). 

 MAMMILLARIA UNISETA. 



Globose, about 2 inches in diameter, 

 simple, somewhat depressed at summit: 

 tubercles 4-angled, dark green: spines 

 6, usually 1-1^. lines long, at first 

 black, finally gray: flower and habitat 

 unknown (MfK 1904, 128). 

 MAMMILLARIA VENUSTA K Br. 



"Simple, becoming caespitose in clus- 

 ters of, in extreme cases, as many as 40; 

 heads 2-4, very rarely, in center of large 

 clusters, 6 cm high, a little less in diam- 

 eter; tubercles thick and short, concave 

 at the end, greenish, purplish to nearly 

 white, glaucous; axils only slightly wool- 

 ly, soon marked; radial spines, 9-15, 

 stout, 6-12 mm long; centrals typically 

 solitary, 10-15 mm, sometimes 2 or 3, in 

 a single specimen 4, porrect-spreading, 

 the 3 upper very short; flowers about 4 

 cm in diameter, rose-color, widely 

 spreading, tube very short; petals lance- 

 olate acute, recurved-spreading; style- 

 branches 5, apparently rosy brown; 

 fruit 1^2-12 cm long, scarlet, linear, cir- 

 cumsissile some distance above the base, 

 nearly dry; seeds oblong-ovate, rather 

 less than 1 mm long", constricted above 

 the basal portion, which is half as long- 

 and nearly as wide as the upper; surface 

 dull, minutely pitted, the pits much ob- 

 scured by delicate intervening striae; hi- 

 lum basal, large and triangular. 



'^Collected by Mr. T. S. Brandegee in 

 the vicinity of San Jose del Cabo, Baja 

 California, in Sept. 1S90. (No. 240, M. 

 Goodrichii, of 'Flora of the Cape Re- 

 gion'); again Sept. 1893, and for the third 

 time last year in numerous living speci- 

 mens. The spines are from pure white, 

 barely tipped with brown, to dark brown, 

 whitish only near the base. The flowers, 

 which appear in September, hide the 

 whole plant, and it is of such low growth 

 as to look like a beautiful cluster of 

 flowers springing from the sand. The 

 fruit appearing in winter is nearly dry 

 ond falls very readily when ripe, leaving 

 most of the seeds in the axillary cup. It 

 is the only circumcissible mammillaria 

 known to me." Katharine Brandeeree, 

 Zoe, 5:8 (Je 1900.). 

 MAMMILLARIA VETULA Mart. 

 M. vivipara Haworth, Suppl. PL Succ. 

 72. A low plant, simple, or usually 

 profusely proliferous and caespitose: 

 12-20 stiff, white, often purple, radial 

 spines, 3-4 lines long, covering- the en- 

 tire plant; centrals 4, 3 pointing up- 

 ward, one the stoutest and shortest 

 downward, rarely less, often more, as 

 many as 8, usually 4-6 lines long; 

 flowers central, an inch and a half 

 long and broad, when fully expanded, 

 with 30 or more delicately fimbriate 

 recurved sepals and 25-40 narrow 

 acuminate purple petals, which are 

 naked or fimbriate at base; filaments 

 whitish or purplish, almost from the 



