THE FORMS OF FLOWERS IN VALERIANA DIOICA. 91 
The Forms of Flowers in Valeriana dioica, L. By Н. P. Grecory, M.A., 
University Lecturer in Botany, Cambridge. (Communicated by А. С. 
SEWARD, F.R.S., Е.Х.) 
(PLATE 8.) 
(Read 17th Deceinber, 1908. ] 
Iv 1877 Hermann Müller * described four forms of Valeriana dioica, L., 
distinguished one from the other by structural peeuliarities of the flowers. 
The descriptions which Müller gave of these forms are :—(1) male, without 
the rudiment of a pistil, with the largest corolla; (2) male, with the rudiment 
of a pistil, with a rather smaller corolla ; (3) female, with distinct rudiments 
of anthers, with a still smaller corolla ; (4) female, with scarcely visible 
rudiments of anthers, with the smallest corolla. 
A somewhat similar case of dimorphie male and female forms, occurring in 
Rhamnus catharticus, is described by Darwin 1. А comparison of Müller's 
figures and descriptions with those of Darwin, suggests that Müllers first 
form of Valeriana dioica corresponds with what Darwin called the « short- 
styled male ? of Æhamnus ; the second form with the * long-styled male” ; 
the third with the *short-styled female,” and the fourth with the « long- 
styled female." 
Darwin's description of the various forms of Rhamnus indicates that we 
are there dealing with a dicecious heterostyled plant. То work experimentally 
with such a plant as Rhamnus is out of the question, but it seemed likely 
that Valeriana dioica offered a parallel ease, in which some results might be 
hoped for from experimental breeding. For several reasons the Valerian 
has proved unsatisfactory as а subject for experimental work, but during the 
past six summers numerous observations have been made upon the forms of 
flowers which occur in the species. It is with these observations that the 
present paper deals. 
In May 1903, forty-six plants of Valeriana dioica were brought in for 
experimental purposes from Dernford Fen, near Cambridge, where they were 
growing wild. These and their offspring (which numbered about four 
hundred), together with numerous wild plants, which were examined from 
time to time at Dernford and Wicken Fens, form the material upon which 
the observations were made. I have no exact record of the total number of 
plants which I have examined, but it is well over a thousand. 
Four fairly definite types of flower can be recognized among the plants 
* “Tas Variiren der Grüsse gefarbter Bliitenhiillen,” Kosmos, Ва. и. 1 77, p. 181. 
T ‘Forms of Flowers,’ p. 204 (in Reprint of 1892). 
H2 
