186 CACTACEA OF THE BOUNDARY. 
confined by the roots of Algarobia. Flowers July and August.— A splendid and very interesting species, 2-4 inches 
high. Tubercles very different in size in different specimens, from 6 or 7 to 10 or 12 and sometimes even 15 lines 
long, generally arranged in 8 spirals. The groove is absent in the tubercles of the young plant ; in the older ones it 
shows itself slightly, and only near the point of the tubercle from the spines downward. In more fully developed 
tubercles it becomes longer ; till in the flower-bearing ones it reaches downward to the lower third, but never to the 
axilla. There it enlarges into the flower-bearing areola. — Radial spines 6-20 lines long, whitish on the upper ones or 
all rose-colored when young ; central spines 1-2} inches long, the lowest one longer and stouter than the rest, mostly 
black, in some specimens paler, straight, or sometimes curved or twisted. Flower 25-3 inches Jong and of the same 
diameter ; deep rose-color or carmine verging to purple; darker along the centre and toward the tip. Fruit 
8 to 10 or 12 lines long. Seeds different in size, 0.7-0.8 line long, short and thick, with a decidedly ventral hilum. 
Albumen distinct, more so than in most other Mamillarie, but the embryo quite similar to them. The scales on the 
ovarium indicate an approach to Echinocactus, though the habit of the plant is decidedly that of a Mamillaria. 
M. dactylothele, Lab., is a variety of this species. 
Subgen. 3. ANHALONIUM,. 
Plante simplices, tuberculate, subinermes. 
Tubercula subfoliacea, triangularia, levia seu supra verrucoso-fissurata. 
Areole florifers supra-axillares (an semper ?), jubato-villosissime. 
Flores ex areolis tuberculorum hornotinorum nascentium oriundi, in vertice congesti, mediocres. 
Ovarium emersum : bacca floris rudimentis coronata, plerumque anno primo maturescens, 
Semina majuscula, nigra, tuberculata. 
These very curious plants, some of them looking more like some Aloé than like a Cactus, can nevertheless not be 
separated from Mamillaria. The seed is the only part of the organs of fructification which seems to offer any charac- 
ter, by having a hard, roughly tuberculated testa in ours, as well as in another Mexican species which I had the 
‘ opportunity to examine. Our species (and probably all the others) has the flower and fruit sessile upon the lower 
part of the tubercle, and elevated above the axil, much as in M. macromeris; but, unlike that plant, the lower part of 
the tubercle is entirely distinct from the upper one. 
23. M. FISSURATA, sp. nov.: e radice crassa napiformi simplex, depresso-globosa seu applanata ; vertice den- 
sissime villoso ; tuberculis e basi applanata dilatata crassis triangularibus inermibus extus infraque levibus seu versus 
inem crenulatum rugosis, supra sulco centrali villoso lateralibusque 2 nudis profunde quadripartitis et sulcis 
transversalibus in tubercula irregularia angulosa numerosa multifidis ; floribus e villo longo sericeo centralibus breviter 
tubulosis ; sepalis sub-20, inferioribus lineari-lanceolatis integris carnosis albidis, superioribus spathulatis cuspidatis ; 
petalis sub-12 spathulatis versus apicem obtusum mucronatum integriusculis seu laceris roseis ; stigmatibus 
5-10 erecto-patulis ; baccis ovatis pallide virescentibus in lana densa occultis ; seminibus obovato-globosis tuber- [18] 
is nigris opacis, hilo basilari transverso ; embryone obovato erecto. (Tab. XVI. 
On hard, gravelly, limestone hills, near Fairy Springs, not far from the mouth of the Pecos, and between that 
river and the San Pedro, Schott, Bigelow; and higher up on the rocks of the cafion of the Rio Grande, Parry. 
Flowers September and October. — The lower part of the plant is top-shaped, covered with the scale-like remains of 
earlier tubercles ; the upper part is hemispherical or depressed and flattened, hardly elevated above the surface of the 
ground, 2-4} inches in diameter. Tubercles in my specimens 6-10 lines long and a little less broad, or sometimes 
the upper warty part “3? inch long and 1} inch wide,” in 5 or 8, or rarely in 13 spiral rows; lower part of tubercles 
flattened, acute at the edges, slightly carinate, more on the upper and less on the lower surface, smooth ; upper and 
part of tubercle triangular in outline, convex, carinate and almost smooth below, convex and variously fissured 
and thereby verrucose above, sharp and crenate on the edges, The principal groove on the upper surface is a longi- 
tudinal one corresponding to the groove of the different species of Coryphantha, and like that villose ; towards its base 
(at the base of the upper or warty part of the tubercle) it expands into the floriferous areola ; upward it ceases just 
under the acutish point of the tubercle, without any trace of an aculeiferous areola or of spines. In the young tubercle 
it is coated by dense, long and straight, white or yellowish, silky wool (about an inch long), which from being exposed 
to the weather gets matted and dirty, and after several years entirely disappears. Two lateral grooves run parallel 
with this, and, together with the many transverse fissures, cut up the upper surface into numerous angular tubercles or 
warts. Flowers central or vertical (in the sense of the term as explained before), borne on the lower smooth part of 
a very young tubercle, which when bearing flower and fruit is somewhat thickened, and takes the shape and functions 
of a short peduncle, bearing laterally the upper part of the tubercle like a small bract ; the axils even of these young 
tubercles are entirely naked, the long wool which covers the lower part of the flower and entirely hides the whole 
fruit being produced entirely from the areola and the central groove. Flower about an inch long, and of the same 
diameter when fully open ; ovary 3 lines long, oval; tube 4-6 lines long; 12 exterior sepals whitish, fleshy, 8 inner 
