LEGUMINIFERZ. 53 
than in the preceding species. Heads } to $ inch long, on stalks 
from 3 to 1 inch in length, with a small white membranous frill- 
like involucre immediately below the flowers, not much exceeding 
the width of the pedicel. Flowers ¢ inch long, pale purplish rose- 
colour. Calyx very strongly ribbed, with slender almost subulate 
teeth ; standard withering, not retaining its shape. Pod ovoid, 
swollen, protruding from the calyx-tube. Plant lively green, 
glabrous. 
The more or less upright stems and stalked heads of purplish 
flowers, with the pods protruding from the swollen ovoid calyces 
when ripe, at once distinguish this rare species. 
Upright Round-headed Trefoil. 
French, 7'réfle Raide. 
SPECIES XV.—TRIFOLIUM HYBRIDUM. Zinn. 
Puate CCCLXI. 
Rootstock many-headed. Stems erect, or decumbent only at the _ 
base, not rooting at the nodes, branched. Lower leaves on long, 
upper ones on short stalks; leaflets oval or obovate, rounded 
at the apex, finely denticulate at the margins. Stipules oblong, 
adnate for less than half their length, with the free portion nar- 
rowly triangular. Flower-heads all axillary, on stalks much ex- 
ceeding their own length and longer than the leaves from which 
they spring, solitary, depressed-globular. Flowers on pedicels as 
long as or longer than the calyx, reflexed after flowering. Calyx- 
tube bell-shaped, bulging at the base on the upper side, faintly 
nerved; teeth nearly equal, subulate, about as long as the tube, 
unaltered in fruit. Corolla more than twice as long as the calyx, 
becoming scarious and striate when covering the pod. Pod 2- to 
4-seeded, longer than the calyx-teeth. Plant sub-glabrous. 
Var. a, genuina. 
T. hybridum, Koch, Syn. Fl. Germ. et Helv. ed. ii. p. 192. Gr. & Godr. FI. de Fr. 
Vol. I. p. 420. 
Stems stout, hollow. Stipules few-nerved. Heads of flowers 
large. 
Var. 8, elegans. 
T. elegans, Savi. Koch (2), Syn. Fl. Germ. et Helv. ed. ii. p. 193. Gr. & Godr. FI. 
de Fr. Vol. I. p. 420. 
Stem weak, decumbent at the base, solid. Stipules several- 
nerved. Leaves more sharply denticulate, and heads of flowers 
smaller than in var. a. 
