I 66 THE CACTACEAE. 



This species was named for T. Stuekert 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 (Bodeker). 



Echinocactus joossensianus Bodeker, 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, near'.y 

 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. 



Illustration: Monatsschr. Kakteenk. 28: 41, as Echinocactus joossensianus. 



19. ECHINOCACTUS kink and Otto, Verh. Ver. Beford. Gartenb. 3:420. 1827. 



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 

 hilum. 



The generic name is from extvos hedgehog, and kclktos 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 tenuis pinus 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 or 

 E. platyacanthus. In the last paragraph of their paper they state that E. tenuispinus 

 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 E. 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. Beford. Gartenb. 3: 420. 1827. 



