CACTUS. 221 
Plants of this genus were among the earliest cacti known to Europeans, by whom they 
were first called Echinomelocactus. ournefort shortened the name to Melocactus and 
Linnaeus again shortened it to Cactus. Under this name these plants generally passed 
until 1827 when Link and Otto restored the name Melocactus. 
At the time that Linnaeus wrote his Species Plantarum only one species of this genus, 
as we now understand it, was known, although Linnaeus included with it all the other 
members of the family; this he called Cactus melocactus. Under this name, however, were 
included several species. For instance, we know that the plants described and figured by 
Bradley came from Nevis and St. Christopher and are different from the Jamaican species. 
Philip Miller in his Gardeners’ Dictionary, published in 1768, described five species in the 
genus Cactus, but only the first two (C. melocactus and C. intortus) belong to the genus as 
now delimited. 
These plants have various common names, but the ones most generally known among 
English speaking people are Turk’s cap or Turk’s head. In Brazil they are called cabeca 
. de frade; in Cuba and Porto Rico, melones. ; 
The name Cactus is of Greek origin, meaning thistle, with reference to the spiny 
armament, but, as here used, comes directly from Melocactus, that name having been 
shortened by Linnaeus. . 
The species of Cactus have a wide distribution; none of them reaches the continental 
United States, but one inhabits Porto Rico and the Virgin Islands. Hemsley (Biol. 
Centr. Amer. Bot. 1: 502) lists four species of Melocactus (M. curvispinus, M. delesserti- 
anus, M. ferox, and M. mammillariaeformis) from Mexico, some of which may belong to 
this genus, but the last one, however, must be referred elsewhere. We have seen only a 
barren Mexican plant, but Dr. C. A. Purpus has reported a species from Tehuantepec. 
M. salvador Murillo, from near Jalapa, was published a few years ago; photographs of this 
plant are at Kew. One species (Cactus maxonii) is known from Guatemala; we have 
this in cultivation. One species (Cactus ruestii) is known from Honduras; this we have 
seen. No species have been reported from the other Central American countries, includ- 
ing Panama. 
Three species have been reported from Colombia (IM. amoenus, M. rubens, and M. obtu- 
stpetalus). M. obtusipetalus is reported from near Bogot4, which is a very unusual habitat. 
We have seen two species from Colombia, one obtained by Mr. Pittier in the Cauca Valley 
and the other brought from Santa Marta by Mr. Curran. No species have been found in 
Ecuador or Chile, but one is known from the foothills of central Peru. No species are 
known from Bolivia, Argentina, Uruguay, or Paraguay. In central and northern Brazil, 
especially along the coast and in the desert regions of the interior, several species occur. 
Our collections indicate four species, although some 14 names, based on Brazilian material, 
have been published. We have seen no specimens from any of the Guianas, although a 
species has been reported recently from Dutch Guiana and is shown in one of our illus- 
trations (fig. 245). Four species have been reported from Venezuela (M. caesius, M. griseus, 
M. lehmannii, and M. cephalenoplus). We have seen one or two species from Venezuela. 
These plants are very common in the West Indies. We have collected them ourselves 
on the four larger islands and many of the smaller ones. Two species have been reported 
from Cuba (Cactus harlowii and Melocactus havannensis), one from Jamaica (M. communis or 
C. melocactus), and several species from Santo Domingo, but we know only one from Porto 
Rico. We also know one from St. Thomas, St. Croix, St. Christopher, and Antigua respect- 
ively, while Boldingh reports one species on St. Eustatius, Saba, and St. Martin respectively. 
We have seen a plant from Tobago but this is not referable to any species known to us. 
The genus is found also on Curagao, Bonaire, and Aruba, and many names have been given 
to what seems to represent a single species on those islands. 
Because of the interest in the species they have been much planted in tropical America. 
