ECHINOCACTUS. 
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9 . Echinocactus horizonthalonius Lemaire, Cact. Gen. Nov. Sp. 19. 1839. 
Echinocactus equitans Scheidweiler, Bull. Acad. Sci. Brux. 6 1 : 88. 1839. 
Echinocactus horizonthalonius curvispinus Salm-Dyck, Cact. Hort. Dyck. 1849. 146. 1850. 
Echinocactus horizonthalonius centrispinus Engelmann, Proc. Amer. Acad. 3: 276. 1856. 
Echinocactus laticostatus Engelmann and Bigelow, Pac. R. Rep. 4: 32. 1856. 
?Echinocactus parryi Engelmann, Proc. Amer. Acad. 3: 276. 1856. 
Echinocactus horizonthalonius dbscurispinus R. Meyer, Monatsschr. Kakteenk. 21: 1S1. 1911. 
Simple, globular or sometimes depressed or short-cylindric, 4 to 25 cm. high, glaucous; ribs 
7 to 13,* obtuse, often spirally arranged; spines 6 to 9, somewhat curved or straight, 2 to 4 cm. long, 
often very stout, more or less flattened, often annulate, reddish or sometimes blackish at base; 
central spine solitary, stouter than the radials; flowers pale rose to pink, 5 to 7 cm. long before ex¬ 
panding, broader than long when fully open; outer perianth-segments linear with more or less pun¬ 
gent tips; inner perianth-segments narrowly oblong, about 3 cm. long; throat of flower short and 
broad, covered with numerous stamens; tube of flower wanting or nearly so; filaments white; style 
pink; stigma-lobes pinkish to olive; ovary and fruit bearing linear scales, their axils very woolly; 
fruit dehiscing by a basal pore, oblong, red, 3 cm. long, clothed with long white wool; seeds 2 mm. 
long, more or less angled, brownish black, papillose; hilum large, lateral but below the middle. 
Type locality: Not cited. 
Distribution: Western Texas, southern New Mexico to Arizona,! and northern Mexico. 
Echinocactus horizontalis (Forster, Handb. Cact. 327. 1846) is given as a synonym of 
this species but it was never described. According to F. E- Lloyd, it is known in Mexico as 
manca caballo. 
This cactus is said to be used in making a Mexican candy. 
Illustrations: Cact. Mex. Bound, pi. 32, f. 6, 7, as Echinocactus parryi; Schelle, Handb. 
Kakteenk. f. 71, as E. horizonthalonius curvispinus ; Bliihende Kakteen 2: pi. 117; Schu¬ 
mann, Gesamtb. Kakteen f. 51; Monatsschr. Kakteenk. 21: 179; Ann. Rep. Smiths. Inst. 
1908: pi. 2, f. 5; Cact. Journ. 1: pi. for March; Diet. Gard. Nicholson 4: 539. f. 21; Suppl. 
335 - L 3571 Cact. Mex. Bound, pi. 31; 32, f. 1 to 5; Forster, Handb. Cact. ed. 2. f. 56, 57; 
Goebel, Pflanz, Schild. 1: f. 48; Lemaire, Icon. Cact. pi. 3; De Laet, Cat. Gen. f. 15; Orcutt, 
Rev. Cact. opp. 41; Watson, Cact. Cult. 106. f. 37; Remark, Kakteenfreund 14; Balt. 
Cact. Journ. 1: 68. 
Plate xx, figure 3, shows a flowering plant collected by E. O. Wooton in the Tortiegas 
Mountains, Las Cruces, New Mexico, in 1905, which bloomed at the New York Botanical 
Garden in July 1917; figure 4 shows the fruit and figure 5 the seed of a plant collected by 
Mrs. S. L- Pattison in southern Texas in 1920. 
UNIDENTIFIED SPECIES DESCRIBED AS ECHINOCACTUS. 
The following species are recorded here because their generic relationship can not be 
determined. They are mostly described without flower or fruit. 
Echinocactus amazonicus Witt, Monatsschr. Kakteenk. 12: 29. 1902. 
Cespitose, each plant 8 to 10 cm. broad, 4 to 5 cm. high, dark green, shining; ribs 11 to 13, 
separated by short intervals; areoles 2 cm. apart, when young woolly, becoming glabrate; spines 8, 
when young chestnut-brown, the lower one longest, sometimes 3 cm. long, the upper ones often 
only 6 mm. long; flowers and fruit unknown. 
Type locality: In the Serra de Tucunare on the Rio Taeutu in northern Brazil. 
This plant is known only from the single collection of Alfred Wauer, and as flowers and 
fruit are both unknown its generic position is in doubt. It is certainly not an Echinocactus 
as we now treat the genus. It may be a young form of some species of Cactus ( Melocactus ). 
*The number of ribs is almost always 8; in small plants we have seen as few as 7; Coulter has reported 10. 
Echinocactus parryi which we have referred here doubtfully was described as having 13. 
fThe Arizona record is based on a plant collected by Dr. Forrest Shreve in Pine County in 1918. Professor 
F. E. Lloyd reports finding the plant at Silver Bell Mountain but we have never seen his specimen. 
