f 
166 THE CACTACEAE. 
This species was named for T. Stuckert who aided Dr. Spegazzini in his studies of 
the cacti of Argentina. 
Figure 180 is from a photograph of an Argentine plant contributed by Dr. Spegazzini. 
23. Gymnocalycium joossensianum (Bédeker). 
Echinocactus joossensianus Bédeker, Monatsschr. Kakteenk. 28: 40. 1918. 
Simple, depressed-globose, somewhat umbilicate at apex; ribs 6 to 9, obtuse, straight, some- 
what tubercled; spines 6 to 9, the lower ones a little longer than the upper ; flowers wine-red, nearly 
central, campanulate with a short tube; inner perianth-segments longer than the outer, oblong- 
obtuse; stigma-lobes 6; fruit fusiform; scales on the fruit few, red-tipped; seeds brownish yellow. 
Type locality: Not definitely cited. 
Distribution: Paraguay or northern Argentina. 
We have not seen specimens of this plant, but from the illustration it is clearly a 
species of Gymnocalycium. 
~ 1 llustration: Monatsschr. Kakteenk. 28: 41, as Echinocactus joossensianus. 
BS am } 19. ECHINOCACTUS Link and Otto, Verh. Ver. Beford. Gartenb. 3: 420. 1827. 
a 
Plants very large, thick, cylindric and many-ribbed, or low and several-ribbed, the top clothed 
with a dense mass of wool or nearly naked; areoles very spiny, large, those on the upper part of old 
plants sometimes united; flowers from the crown of the plant, often partly hidden by the dense wool 
at the top, these usually yellow, rarely pink, of medium size; outer perianth-segments narrow, 
sometimes terminating in pungent tips; inner perianth-segments oblong, thinner than the outer, 
the inner ones obtuse; scales on the flower-tube numerous, imbricate, persistent, pungent; scales 
on the ovary small, often linear, their axils filled with matted wool; fruit densely covered with white 
wool, thin-walled, oblong; seeds blackish, smooth, shining, or rarely papillose, with a small subbasal 
ilum. 
The generic name is from txivos hedgehog, and xax7tos cactus, referring to the spiny 
armament. 
The genus Echinocactus, as treated by Karl Schumann in his monograph (Gesamtb. 
Kakteen 290 to 452. 1898), contains 138 species, while more than 1,025 names have been 
used in the genus. Our review of Echinocactus convinces us that there is a number of 
distinct genera, several of which have already been proposed and others entirely new. 
Before making these segregates it was necessary to establish the type of the genus which was 
proposed in 1827. Before that time the species of Echinocactus were usually considered as 
belonging to the genus Melocactus. In that year Link and Otto* established the genus 
Echinocactus, describing and illustrating 14 species. The illustrations, however, must 
have been made and engraved before it was decided to establish the genus for they all bear a 
Melocactus legend. Since these 14 species do not belong to the same genus, it is important 
to establish the type. 
In their introduction Link and Otto state that Echinocactus tenuispinus and E. platya- 
canthus have the flowers of a Cereus and, for this reason, as well as the absence of a cepha- 
lium, were separated as Echinocactus. ‘The other 12 species referred there, whose flowers 
they did not know, were evidently thus referred from the supposed lack of a cephalium. 
It seems, therefore, the type of the genus Echinocactus should be either E. tenuispinus of 
E. platyacanthus. In the last paragraph of their paper they state that E. tenuis pinus 
should probably be referred to Cereus and that E. platyacanthus and 7 other species belong 
to Echinocactus. We therefore designate Echinocactus platyacanthus Link and Otto.as the 
type of the genus. We recognize 9 species of Echinocactus. 
This group to which FE. platyacanthus belongs is characterized by a densely woolly 
crown to the plant, very woolly, thin-skinned fruit, and smooth seed, with a lateral hilum. 
As thus characterized, the genus contains at least 6 Mexican species, although there are 
* Verh. Ver. Beférd. Gartenb. 3: 420. 1827. 
