Note on Abnormal Flowers in Orchis purpurea, Huds. 
BY 
J. R. MATTHEWS, M.A., 
Assistant Lecturer in Botany , Birkbeck College, London . 
With four Figures in the Text. 
I N^specimens of Orchis purpurea, Huds. gathered in Kent by one of the 
advanced students at Birkbeck College, several flowers were found to 
show various abnormalities in structure. A large number of inflorescences 
were examined, both in the field and in the laboratory, and out of three 
spikes sixteen flowers were obtained which presented deviations from 
the ordinary type of conformation. 
The main abnormality consisted in an increase in the number of 
stamens. Orchis purpurea, like the majority of Orchids, develops normally 
only the anterior stamen of the outer whorl, 
A i (Fig. i), while the other members, A2, 
A3, are represented by staminodes in the 
shape of auricles (Fig. 2). In some of 
the abnormal flowers the staminodes were 
replaced by stamens having both pollinia 
fully developed, so that the flower became 
triandrous (Fig. 3). In several cases only one 
staminode was transformed and diandrous 
flowers resulted, the stamens being either 
Ai, a 2, or ai, A3. In these diandrous forms 
the staminode which was not transformed 
maintained its ordinary position on the side 
of the column. This would seem to show 
that the staminodes are potentially stamens, 
and their appearance as such in a fertile 
condition goes pari passu with their disappearance as staminodes. This 
also means that the additional stamens are not derived from any other 
normally suppressed members of the androecial whorls. In one case 
a further departure from the type was observed. The stamens ai, A2, 
were fertile, and the posterior stamen of the inner whorl <23, which is 
usually completely suppressed, was represented by a pollinium arising 
[Annals of Botany, Vol. XXIX. No. CXIII. January, 1915.] 
Fig. 1. Diagram of Orchis flower. 
The stamens A2, A3, are represented 
by staminodes on the side of the 
column. 
