m 



THE FLORAL ENVELOPES IN GRAMINE.T: AND CYPERACE^. 



somewhat common abnormal growth of C. f/lauca (in which the 

 female spikes become componnd) exhibits the normal or universal 

 law of the growth of the inflorescence of the whole genus (See 

 paper already cited ; Journ. Bot., June, 1873). 



Tab. a. — Form of ochrea and bracts in Carex riparia. 



Fip:. 1. — a, leafy bract (partially removed) below a male spike ; b, bract-like 

 utriculus at the base of of male spike ; c, stigmas of nut within h. 



Fig. 2. — Axillary biact oi- ochrea at the base of secondary axis of female 

 spikes of C. riparia ; the dotted or wavy line indicates the outline of the form 

 which the bract takes at the base of the upper spikes, where it has already a 

 tendency to inflate and assume the shape of the utriculus, and to form veins. 



Fig. 3. — The transformation of the Ijracts into the utriculus is well seen in 

 the male spikes of Carex riparia. This fig. shews one of these bracts. The 

 lower portion of the bract is coloured and veined almost as in the perfectly- 

 formed uti'iculus of the fertile spikes, and the sides lengthen for the teeth. 



1 ,■) (i 



Figs, i & ;'). — Scales of male catkin (jf Carex ripitnu. 



Fig. (j. — Utricular bract (axillary bract) at the base of a male catkin of C. 

 riparia ; this bract was not clasping. 



Fig. 7. — n, this scale-like ochrea is situate at the base of a fertile spike; 

 it shows tln^ commencement of the transformation of the ochrea (nxillary bract) 

 into the utriculus; it is scale-like, with the exception of a fleshy green mass 

 with side neiwes distinctly visible. The central nerve of the scale has 

 disappeared, h and c, forms not nnfrequently assumed by the outer bracts 

 subti'uding the uliiculus in the female spikes. 



