Polymorphism in the Flower of Silene maritima. r i 
are the normal number of stamens present and the stigmas vary, as 
is usual, from three to five. 
A single plant was found at Cley with lateral lobelets as in f. 
lobata, but with somewhat smaller flowers (Text-fig. b): the 
stamens were all reduced to staminodes and the coronal scales were 
small. Whether this plant is more nearly related to f. lobata or to 
the next form is uncertain, but in the absence of corroborative 
specimens bearing this type of flower, a form name would be 
premature. 
The next type, which will be best designated by the name f. 
foemina is very distinct both superficially and in detail. The flowers 
are much smaller than in any of the other forms, varying in diameter 
from about 10 to 15 mm., and are usually slightly purplish in colour. 
The petals are widely separated from one another and deeply cleft 
into divergent lobes which may bear at their base coronal scales 
(Text-fig. f); these are either very small or almost absent. 
The most important feature of this plant is the unisexual 
character of its flowers which, as in the sub-form of f. lobata, possess 
no functional stamens, these organs having been reduced to stami¬ 
nodes. They are short, of about 5 to 6 mm. in length and bear 
very small abortive anthers at their apex. Plate I, figs. 4a, 4b, 
and 4c, illustrate three flowers : one of these (4c) has had part of 
the calyx and corolla removed to shew the staminodes which 
scarcely reach to the apex of the ovary. 
The last type to be described has only been found at Blakeney 
Point, where three specimens now grow ; of these the first was found 
by Mr. R. J. Pinchin some years ago and two others in 1911. 
All the essential organs have in this form become converted 
into petals and a considerable amount of “ dedoublement ” has taken 
place often resulting in a splitting of the calyx—a common feature 
in garden pinks which these flowers greatly resemble. In size the 
blooms vary from 30 to 40 mm. in diameter and are, if anything, 
slightly more cream-coloured than the single flowered forms. A 
plant growing in its natural habitat is shewn in Plate 1, fig. 6 with 
Arenaria peploides in the foreground. 
The unisexuality met with in two of the types described may 
be regarded as a further advance upon the lines indicated by the 
marked protandry of the hermaphrodite forms. For whilst this 
mechanism ensures fertilisation by a different flower it does not of 
course preclude fertilisation by the pollen of a bloom on the same 
plant, as does the total suppression of functional male organs found 
in f. foemina, 
