SYNOPSIS OF THE CACTACEAZ OF THE UNITED STATES. 129 
San Diego, California. — Two or three inches high. Radial spines 2$~-3} lines long ; the lower central spine a 
little longer. Flowers apparently yellowish-white, and half an inch in diameter 
§ 3. Setos#, Salm. 
9. M. Bicotor, Lehm. : depressa, ovata, s. cylindracea, prolifera; axillis lanatis ; tuberculis parvulis conicis ; 
eh exterioribus 16-20 tenuissimis recurvato-radiantibus, centralibus 2-4 rigidis, majoribus albis = nigris inter- 
dum pe ae ipa supremo plerumque longissimo incurvo ; floribus parvulis purpureis ; stigmatibus 
ndant the calcareous hills of the Rio Grande below Laredo, Texas, Dr. Poselger : fl. Palas and July. — 
Plant oa8 inches high, the larger specimens 2-3 inches in diameter; radial spines 1-2, lower central ones 4-5, the 
upper 6-10 lines long. Flower about 9 lines long. 
§ 4. CenTRISPINE, Salm. (All our species are simple and have a milky juice.) 
10. M. Heypert, Muhlenpf. (1848): simplex, depresso-globosa; tuberculis elongatis pyramidatis ie i 
rangulatis ; aculeis radiantibus 10-20 rectis, inferioribus longioribus, centrali singulo breviore ; floribus lateralibus 
sordide rubellis baccis elongato-clavatis ; seminibus parvis rugulosis fulvi 
Var. a. APPLANATA (M. applanata, E. in Pl. Lindh. 1850): vertice sacle s. depresso, aculeis radialibus 15-22. 
Var. 8. HEMISPHARICA (M. iierictaphaicd, E. 1. c.) : vertice convexo, aculeis radialibus 9-12. 
From San Antonio and New Braunfels, Texas, to Matamoras and westward to El Paso: fl. April, May. — 
Var. a. is the Northern and Western, and 8. the Southern form. — M. declivis, Dietr. seems to belong here ; but I 
have never met with a description of this plant. 
1l. M. meracantua, E. in B. C. R.: hemispherica ; tuberculis quadrangulato-pyramidatis compressis; aculeis 
paucis (5-9) rigidis rectis s. recurvatis, oar paulo longioribus, centrali singulo erecto s, sursum flexo et cum 
ceteris radiante ; a. et baccis prec 
Wes as and New Mexico. es similar to the last ; but tubercles larger, more compressed, more loosely 
arranged ; the tent fewer and stouter; perhaps only a variety of it. 
12. M. gumrrer, E. in Wisl. Rep. Similar to the last two, but stouter ; flower larger, darker, but [264] 
otherwise little different. cen ie soe 10-12 ; the lower ones much stouter ind longer than the upper 
ones ; central spines 1 or 2, shorte 
§5. LonarmamM 4, Salm. 
13. M. spHarica, Dietr. : prolifera, cxespitosa ; tuberculis ovato-elongatis acutatis ; aculeis setaceis radialibus 
12-14, centrali singulo reste vix robustiore ; floris magni tubo supra ovarium emersum constricto elongato ; 
petalis flavis acuminato-aris 
ill-sides on the Rio de near Eagle Pass; also Corpus Christi, on the Gulf. — Single specimens clavate, 
but often forming dense hemispherical masses. Tubereles 6-8 lines, spines 3-5 lines long. Flower 14-2 inches long. 
Fruit not seen. 
Subgen. 2. CorypHanTHA. Flores e basi tuberculorum hornotinorum aculeiferorum sulcatorum, vel in vertice 
ipso oriundi ; ovarium emersum 
§ 1. ALBIFLORA. 
14, M. paprracanTHA, E. in Pl. Fendl. (Mem. Amer. Acad. 1849). “ This interesting plant has been collected 
only in a single specimen, near Santa Fé, which, together with the dried flowers, is in my possession. Shape of tuber- 
cles not well distinguishable, doubtful whether sulcate or not ; the lower ones proliferous. Spines compressed, flexible, 
of the consistency of stiff paper; 8 radiating and 3 or 4 central; the lowest one of these longest and broadest. 
Flowers white, central, an inch or more in length and width. Fruit not seen. 
§ 2. FLAVIFLORA. 
« Laziflore. (The originally central flowers are pushed aside by the continuous development of new tubercles.) 
15. M. Norra, E. : simplex s. prolifera, czespitosa ; aculeis radialibus 10-17 setaceis rectis plerumque puberulis 
albidis, centrali singulo robustiore sepius deficiente ; sepalis fimbriatis et petalis flavidis apice parce denticulatis 
lanceolatis, s. lineari-lanceolatis acutis; stigmatibus 2-8 erectis vel patulis; bacca subglobosa tuberculis breviore 
coccinea ; seminibus globosis scrobiculatis nigris. 
ar. a. BOREALIS (M. Nuttallii, E. lc. Cactus mamillaris, Nutt. Gen., 1818, non L.) : subsimplex ; aculeis 
setaceis 13-17 cum centrali seepe deficiente puberulis ; stigmatibus 2-5; baccis seminibusque minoribus 
ar. B. caspitosa (M. similis, E. in Pl. Lindh. 1845) : ceespitosa ; aculeis radialibus 12-15 cuberuiig [265] 
centrali plerumque deficiente ; floribus baccis seminibusque majoribus ; stigmatibus 5 patulis. 
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