5i 



Cacti.— Orcutt. 



52 



MAM MILLAR I A 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 y± 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 axils 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 base, forming numer- 

 ous offsets in the axils of the 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, usually 

 10-50 — but in one, perhaps not exceptional 

 case, I 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 1% 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 TOALDOAE Lehm. 

 MAMMILLARIA UMBTIINA Eh. 

 MAMMILLARIA VALIDA Web. 

 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. sing'.e specimen 4, porrect-spreadig, 

 the 3 upper very short; flowers about 4 

 cm in diameter, rose-co'lor, widely 

 spreading, tube very short; petals lance- 

 olate acute, recurved-spreading; style- 

 branches 5, apparently rosy brown; 

 fruit 1%-12 cm long, scarlet, linear, cir- 

 cumsclssile some distance above the base, 

 nearly dry; seeds oblong-obovate, rather 

 less f han one mm long, constricted above 

 the basal portion, which is half as long 

 and nearly as wide as the upper; surface 

 dull, minutelv pitted, the pits much ob- 

 scured by delicate intervemng striae; hi- 

 lum basal, large and triangular. 



"Collected by Mr. T. S. Brandegee in 

 the vicinity of Sa»n Jose del Cabo, Baja 

 California, in Sept. 1890. (No. 24Q, 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 app earing in winter is nearly dry 

 and falls very readily 1 when ripe, leaving 

 most of the seeds in the axillary cup. It 

 is the only circumcissile Mammillaria 

 known to me."— Katherine Brandegee, 

 Zoe, 5:8 (Je 1900). 



MAMMILLARIA VETULA Mart. 



MAMMILLARIA WILCOXI Tourmey. 



Usual: y simple, depressed-globose; 14-16 

 slender subulate whitish radials 10 mm 

 long; solitary hooked central brownish; 

 axilq naked. Fruit (16 O 1896) flesh color 

 faintly tinged with carmine, the black 

 seeds showing through the transparent 

 epidermis. Near Congress and Benson, 

 Arizona (Orcutt). 

 MAMMILLARIA WILDII Dietr. 

 MAMMILLARIA WRIGHTII E. 

 MAMMILLARIA ZEPHYRANTHOIDES 



Scheidw. 



Mamillopsis senilis Web, is Mammillaria 

 senilis Lodd. ., 



Genus MELOOACTUS De Canclolle. 



Globose fleshy plants 1-3 feet in diame- 

 ter, regularly ribbed, ribs bearing clus- 

 ters of spines, surmounted with a woolly 

 cylindrical cap closely cet with softer 

 spines, upon which the small tubular red 

 or rose-colored flowers are borne. Of lit- 

 tle va^ue hortieulturally and rarely cul- 

 tivated with success. Generally found in 

 rocky or candy dry situations in tropical 

 America and West Indies. 



MELOC ACTUS VIRIDESCENS Nutt. 



NuttaM ex Teschem in J Bost Soc Nat 

 Hist 5:293 (1845).— A synonym of Echino- 

 cactus viridescens. 



The Meiocacti are natives of the West 

 Indies, and tropical America. 



Genus MYRTTLLOCACTUS Console. 

 MYRTILLOCACTUS GEOMETRIZANS C 

 Oereus geometrizans Mart. 

 Cereus cochal Orcutt. 



Genus PELECYPHORA Elarenb. 



PELECY(PHORA ASMLLIFORMIS Ehrenb. 



The Hatchet cactus is a little gem 

 from Mexico, so-called from the shape 

 of the tubercles. It bloomed in San 

 Diego on May day, scarce % inch in 

 length and breadth, with thirteen 

 bright magenta colored petals and 

 seven or eight pale lavendar sepals, 

 the four stigmata white, style and fila- 

 ments tinged with purple, and anthers 

 bright orange. The largest plant 



