DICHAEA TRICHOCARPA AND 
DICHAEA SQUARROSA 
BY 
Louis O. WILLIAMS 
For MANY YEARS Dichaea trichocarpa has been the 
name applied to a common species of Mexican Dichaea 
which, in 1840, Lindley had described as Dichaea squar- 
rosa. Fr. Krinzlin, in his monograph of the genus, in 
1923, placed the two species together. 
Lindley originally described Dichaea squarrosa from 
a specimen collected by Th. Hartweg at ‘‘ Mountain of 
Tuguila”’ in June. The locality is not known to me, but 
Hartweg was in Mexico in June 1887 and June 1888. 
In June 1837, he was probably either in the present state 
of Guanajuato or in Jalisco. In June 1838, he was prob- 
ably in Michoacan. 
A photograph of the Hartweg specimen (in Lindley’s 
herbarium) is in the Ames Herbarium. Three other spec- 
imens were subsequently added to the sheet which con- 
tains the type, two from Cuba and one from Mexico. In 
one corner of the sheet an analytical drawing of a flower 
has been added. The drawing seems to represent Dichaea 
trichocarpa and was possibly made from one of the Cuban 
specimens. 
Lindley’s original description of Dichaea squarrosa is 
rather inadequate, but he does mention that the flowers 
are large for the genus and apparently white, —both state- 
ments being true when applied to the species of the 
Pacific slope in Mexico but hardly true of the small- 
flowered D. trichocarpa of the West Indies and Central 
America. 
Dichaea trichocarpa (the small-flowered species) is not 
known to occur on the Pacific slope, that part of Mex- 
ico where Hartweg must have collected the type of D. 
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