60 THE CACTACEAE. 
Riimpler, Sukkulenten 208. f. 118; Gartenflora 34: 25; Watson, Cact. Cult. 189. f. 75; ed. 
3. f. 52; Cycl. Amer. Hort. Bailey 1: 203. f. 303; Stand. Cycl. Hort. Bailey 2: f. 718; Ilustr. 
Hort. 5: pl. 186; Forster, Handb. Cact. ed. 2. 237. f. 21; Cact. Journ. 1: 107, 149; Krook, 
Handb. Cact. 34; Ann. Rep. Smiths. Inst. 1908: pl. 14, f. 6; Palmer, Cult. Cact. 117; 
Schelle, Handb. Kakteenk. 275. f. 197; Monatsschr. Kakteenk. 29: 81; Weinberg, Cacti 23; 
Knippel, Kakteen pl. 28; Mollers Deutsche Gart. Zeit. 25: 477. f. 11, No. 3; Garten- 
Zeitung 4: 218. f. 50; Blanc, Cacti 78. No. 1710; West Amer. Sci. 11: 8; Balt. Cact. Journ. 
1: 89; 2: 164; Floralia 42: 369; Remark, Kakteenfreund 22; Haage, Cact. Kultur ed. 2. 206. 
Figure 56 is reproduced from a painting made by Miss E. I. Schutt in 1907, of a plant 
sent from San Luis Potosi in 1905 by Dr. E. Palmer. 
“> | 
_/O-) 11, PHELLOSPERMA gen. nov. 
A globular to cylindric, usually cespitose cactus with a large, fleshy, branched root; tubercles not 
grooved above, not milky; flowers borne in axils of old tubercles, funnel-shaped; fruit globular to 
cylindric, red, depressed at apex; seeds large (for this group), dull black, not pitted but rugose, with 
a thick corky base nearly as large as the body. 
Type species: Mammillaria tetrancistra Engelmann. 
This genus differs from all its relatives in its very peculiar seeds. ‘The flower, in its 
shape and origin, suggests the following genus, but in its color and size resembles Cory- 
phantha radiosa. A single species is known, native of the western United States. 
The generic name is from deANés cork, and o7épua seed, referring to the corky base of 
the seed. 
>1. Phellosperma tetrancistra (Engelmann). 
?Mammillaria tetrancistra Engelmann, Amer. Journ. Sci. II. 14: 337. 1852. 
ammillaria phellosperma Engelmann, Proc. Amer. Acad. 3: 262. 1856. 
Cactus phellospermus Kuntze, Rev. Gen. Pl. 1: 261. 1891. 
Cactus tetrancistrus Coulter, Contr. U. S. Nat. Herb. 3: 104. 1894. 
Solitary or cespitose, cylindric; sometimes becoming very large and then 3 
dm. long, usually very spiny; root elongated, carrot-shaped or sometimes 
branched; tubercles terete, often elongated, their axils naked; radial spines numer- 
ous, acicular, white or sometimes with a brown tip, not pungent; central spines 1 to 
4, stouter and longer than the radials, often brown or black, one or all strongly 
hooked; flower 3.5 to 4 cm. long, purple; base of tube slender, greenish, naked; jaye, 57,—Seed of 
scales and outer perianth-segments ciliate; style and stigma-lobes cream-colored ; Phellosperma 
fruit rather variable in size, sometimes 3.7 cm. long, becoming dry in age, with a tetrancistra. 
depressed umbilicus; seeds black, dull, 2 mm. long. 
Type locality: San Felipe, California. 
Distribution: Western Arizona, southeastern California, southern Utah, and southern 
Nevada; probably northern Lower California. 
Mr. C. R. Orcutt, under date of March 5, 1922, comments on the distribution of this 
plant as follows: 
“It reaches its greatest development on sandy and gravelly slopes near the White Water River 
east of Banning, California. It no doubt enters Lower California, for I believe that I have found it 
within a mile of the boundary line. It is comparatively rare in Arizona.” 
We have seen no specimens from Utah, but suspect that the plants from that state 
which have been referred to Mammillaria grahami probably belong here. The species 
should be looked for in northern Lower California and Sonora. 
Illustrations: Cact. Mex. Bound. pl. 7; Engler and Prantl, Pflanzenfam. 3°*: 162. f. 
56, B; Cact. Journ. 1: pl. for February; Bol. Direccion Estudios Biol. 2: f. 3; Monatsschr. 
Kakteenk. 20: 167, as Mammillaria phellosperma. 
Figure 58 is from a photograph of a plant sent from California in 1921 by E. C. Rost; 
figure 57 shows a seed taken from a plant sent by Loren G. Polhamus in 1921 from Bard, 
California. 
