CACTUS. 



233 



Ribs 10, vertical, stout, 5 cm. high, somewhat repand, acute, somewhat inflated at the areoles; 

 areoles 5 cm. apart; spines up to 11, about 2.5 cm. long, rigid; radial spines light brown with trans- 

 verse striations; lateral spines more or less recurved or reflexed; cephalium small; flowers rose- 

 colored, twice the size of those of Cactus meloctacus; perianth-segments oblong, rounded or obtuse 

 at apex; style white; stigma-lobes 6. 



Type locality: Santa Fe de Bogota, Colombia. 



Distribution: Colombia. 



The probabilities are that this species is not native at Bogota but that it was in culti- 

 vation there, specimens having been sent from lower altitudes. Mr. Pittier found a species 

 at Venticas del Dagua, Cauca, in the western Cordillera of Colombia, altitude 1,000 meters, 

 which we are disposed to refer here. Dr. F. W. Pennell and Mr. E. P. Killip sent us from 

 this same locality in June 1922 (No. 5415) a single living plant. This specimen is over 

 2 dm. in diameter and has 14 ribs; the radial spines are usually 8, spreading or a little 

 curved backward, 2 cm. long or more; in addition to these spines there are 2 or 3 short 

 ones (3 to 7 mm. long) from the upper part of the spine-areoles which make the upper 

 stout radial appear sub-central; in addition to these there is one stout central spine, por- 

 reet or ascending, 2 to 2.5 cm. long; the spines were probably brown at first, but in age 

 are pale, almost gray. The cephalium is very small. 



Dr. Rusby collected in 191 7 specimens of this or a related species on an arid plain near 

 Cabrello on the Cabrero River, Colombia. We have studied a fragmentary specimen 

 collected by J. F. Holton at Opia, Colombia, in 1852 (No. 728), preserved in the Torrey 

 Herbarium, which has only 6 spines at each areole and these all radial. 



13. Cactus caesius (Wendland) Britton and Rose, Bull. Dept. Agr. Trinidad 19: 86. 1921. 



Melocactus caesius Wendland in Miquel, Nov. Act. Nat. Cur. 18: Suppl. 1. 184. 



Melocactus griscus Wendland in Miquel, Nov. Act. Nat. Cur. 18: Suppl. 1. 185. 



Melocactus cephalenoplus Lemaire, Hort. Univ. 2: 128. 1841. 



Melocactus caesius griseus Forster, Handb. Cact. 263. 1846. 



Melocactus humilis Suringar, Versl. Med. Akad. Wetensch. III. 6: 459. 1889. 



1841. 

 1841. 



Plants globose, depressed, or narrowed above, 1 to 2 dm. high; ribs 10 to 15, prominent, acute, 

 2 cm. high; areoles circular, white-woolly when young, 2 to 3 cm. apart; radial spines about 8, 

 spreading, horn-colored; central spines similar to the radials, about 2 cm. long; cephalium broad and 

 low, composed of white wool and brown bristles, broader than the apex of the plant body; fruit 

 obovoid, wine-colored, up to 3 cm. long, 1 to 1.5 cm. thick. 



Type locality: La Guayra, Venezuela. 



Distribution: Coast of Venezuela and Colombia; 

 Patos Island, Trinidad; and perhaps Dutch Guiana. 



This species has recently been collected by Henry 

 Pittier at the type locality. His specimens show a 

 variation in the number of ribs of from 10 to 14 and 

 probably represent the two forms which Wendland 

 described as different species. Mr. Pittier's plants show 

 considerable variation but hardly seem to warrant the 

 recognition of two species. 



In September 1920 Dr. Gerold Stahel of Para- 

 maribo, Surinam, sent us a photograph of a group of 

 Cactus plants which we tentatively refer here. The 

 living specimens which he collected for us were lost a 

 week after he had collected them through the indifference 

 of his camp helpers. According to Dr. Stahel, the plants 

 were found near the big Raleigh Falls on the Upper 

 Coppename River. They grow on the entirely nude rocks of the Volkberg and are usually 

 found solitary. 



t;. 244. Cactus caesius. 



