18 UNITED STATES AND MEXICAN BOUNDARY. 
densa occultis; seminibus obovato-globosis tuberculatis nigris opacis, hilo basilari trans- 
verso; embryone obovato erecto. (Plate 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: fl. September and October.—The lower part of the plant is 
top-shaped, covered with the scale-like remains of the earlier tubercles ; the upper part is hem- 
ispherical 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 some- 
times the upper warty part ‘‘? inch long and 14 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 he 
upper and less on the lower surface, smooth. Upper and exposed part 6f 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 longitudinal 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, upwards 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 penduncle, 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 
— 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 ones spathu- 
late, mucronate, with rose-colored edges 6-9 lines long, 2 lines wide ; petals about 12 ina single 
series, 9 lines tong; 2 lines bela rose or pink-colored ; stamens numerous, white with orange 
anthers ; style white, expanding into a funnel-shaped irregularly 5-10 parted light-yellow 
stigma. Fruit oval, crowned with the remains of the flower, about 5 lines long, juicy. Seed 
0.8 line long, strongly tuberculated, the transverse and somewhat truncate hilum basilar. 
II. ECHINOCACTUS, Link and Otto. . 
1. E. ScHEERIT, Salm: e radice tereti elongata parvus, globosus seu ovatus ; costis 13 obtusis 
interruptis ; tuberculis ovatis obtusis supra ad medium sulcatis ; areolis ores evbiGaiatts tine: 
oribus albo-tomentosis ; aculeis radialibus 15-18 setaceis rigidis rectis seu plerumque “aifto 
recurvatis albidis stramineisve apice fuscatis, summo interdum elongato wii gitids 3-4 
angulatis ‘variegatis fusco-atris, superioribus rectis sursum divaricatis Woligtare: inferiore 
orr t he ; t i :: 1s j 7 48 S . Pet ge | 
Pt i - amato ean _ ane ie vertice cae sepalis exterioribus 13 squamiformibus, 
Ange ie auriculatis margine membranaceo laceris ciliatis. superior; : 
ot Lipa itis gs Le said hE pat ahs : » Superioribus ovatis 
integri usculis, sepalis interioribus: 8 lineari-oblongis obtusis; petalis 13 lineari-lanceolatis 
acutis flavo-virescentibus ; stigmatibus 8 linearibus flavis ; bacca virescente indistincte squa- 
