THOMPSONELLA, A NEW GENUS OF CRASSULACEAE 
FROM MEXICO. 
By N. L. Brrrron and J. N. Rose. 
In 1905 E'cheveria minutifora first bloomed in cultivation. It 
flowered in the Missouri Botanical Garden, the New York Botanical 
Garden, and one of the greenhouses of the Department of Agriculture 
in Washington at the same time. It was studied independently by 
the writers and Mr. C. Hf. Thompson, and all reached the conclusion 
that it represented a distinct generic type. Material has repeatedly 
flowered since that time, and now we feel justified in proposing this 
new genus, named in honor of Charles Henry Thompson of the 
Missouri Botanical Garden. 
In 1907 Mr. C. G. Pringle collected a second species, which flowered 
in the spring of 1908. This is described below. 
Mr. Thompson has had under observation for several years two very 
distinct species, one of which is probably 7. ménutifora and the 
other an undescribed species. It seems best not to describe this 
species at present, but to wait until further field work has been done. 
Several years ago a plant bloomed in Washington which seemed to 
suggest a fourth species, but as there is some doubt as to place of 
collection it seems best to delay the publication of this also. The 
genus with two species is described as follows: 
Thompsonella Britton & Rose. 
Acaulescent; basal leaves few, spreading, thick, oblong; inflorescence a loose 
simple spike or in large specimens more or less compound: sepals 5, turgid, 
erect, clavate: corolla somewhat angled in the bud, rotate, the tube proper very 
short, the lobes lanceolate, spreading horizontally or somewhat detlexed between 
the sepals: stamens 10, erect, about as long as the petals; carpels erect, con- 
stricted at base; styles slender; scales minute. 
Type species Echeveria minutifiora Rose. 
The inflorescence is very unlike any other in this family which we have yet 
studied. The flowers are arranged in spirals of three and are not. strictly 
axillary, but stand, though directly over, at some distance above the subtending 
bract; they are very unlike those of all the true Echeverias in having a strictly 
rotate corolla and thinner petals. 
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