[Crown Copyright Reserved.} 
ROYAL BOTANIC GARDENS, KEW. 
BULLETIN 
OF 
MISCELLANEOUS INFORMATION, 
No. 3.) (19138. 
XII.—CATASETUM DARWINIANUM. 
R. A. Roure. 
The accompanying plate represents a plant of Catasetum Dar- 
wintanum, Rolfe, bearing male and female flowers on the same 
inflorescence. The plant flowered last autumn in the Kew collection, 
with a second plant which bore only male flowers. Both specimens 
are divisions of a single plant which in 1888 produced both sexes on 
separate inflorescences, one of about 16 male flowers on one side of 
the pseudobulb and one of three females on the other side. In the 
present case the three upper flowers are males, the next female, and 
the lower one is in a transition state, the lip being most like the 
female in shape, but the sepals and petals most like the males, while 
the pollinia are almost normally developed. It may be added that 
in the female flower the anther case and the pollinia—both of 
male origin—were suppressed, while the stipes and gland of the 
pollinarium—which belong to the rostellum, and are therefore female 
in origin—were developed. The lip of the female, it will be 
observed, is hood-shaped and uppermost, while the sepals and petals 
are recurved and rather fleshy in substance, and the column very 
short and stout, with a slender apiculus. In the males the lip is 
inferior and consists of an ovate-oblong body, slightly convex and 
tridentate at the apex, and concave or witha shallow sac at the base. 
The sepals are lanceolate and spreading, and the somewhat narrower 
petals are parallel and situated in front of and appressed to the 
upper sepal, and therefore hardly distinguishable in the photograph. 
The column is longer than in the female, much more slender, an 
bears a pair of slender somewhat diverging sensitive antennae, 
which are totally absent from the female. Another remarkable 
difference between the sexes is that the female flowers are green, 
with a few din urple markings, while the males have lurid 
reddish-purple sepals and petals, and the lip is heavily spotted with 
blackish-brown on a dull green ground. 
The phenomena here illustrated were long a profound puzzle to 
botanists, and plants bearing female flowers only were originally 
referred to a distinct genus by Lindley, under the name of Mona- 
chanthus, while the males of certain species, structurally identica 
(28996—6a, ) Wt. 212—780. 1125, 4/13. D&S, 
