A THREE-SPURRED FORM OF THE LARGER 
BUTTERFLY ORCHIS (Habenaria chlorantha Bab. 
var. tricalcarata Helmsley) 
By G. LISTER. 
HE Club’s herbarium at the Essex Museum contains 
I several line typical examples of the Larger Butterfly 
Orchis, collected in various places. Amongst them, on a sheet 
marked “ex-herb. Wm. Moore,” is a remarkable variety, col¬ 
lected in May 1893, in Braintree Green Wood. Instead of 
the usual long lax spike of large white flowers, this specimen 
has a dense spike ot about fifteen rather small greenish-white 
flowers, all of which differ in construction from that of the normal 
form. 
The typical Larger Butterfly Orchis has a broad upper sepal, 
two long spreading lateral sepals, two narrow petals ascending 
on either side of the upper sepal, while the third petal forms a 
long greenish-white lip with a slender tubular spur, containing 
honey and twice as long as the lip. In Mr. Moore’s specimen, 
the upper sepal and two lateral petals are alike and narrowly 
triangular ; the lateral sepals resemble the lip in all respects, 
except that they are shorter ; each is provided with a long 
honev-bearing spur ; the single stamen appears to have had 
Well-developed pollinea with sticky discs, diverging even more 
than usual from each other, as they lie above and outside the 
openings into the three spurs. The stigma does not seem to 
have been functional ; no trace of ovules was found ; more¬ 
over, the ovary has not the usual twist, so that the spurs 
of the flower are directed more or less upward, instead of down¬ 
ward. 
This strange variety appears to be very uncommon. A similar 
specimen, found near Sherborne, Dorset, in June 1906, was 
described and figured by W. B. Hemslev in the Journal o\ the 
Linnean Society, Bot., 38, p. 0, pi. 1, as a new variety, Platanthera 
chlorantha Custor var. tricalcar ata. In the same volume, Mr. 
Hemslev described another three-spurred form of the Butterfly 
Orchis, found near Bath about the year 1902 ; but the flowers 
in this have the lateral petals, not the lateral sepals, provided 
with long spurs (op. cit., p. 391, figs. 1, 2.). 
