1914] WINTON—ALFALFA AND CLOVERS 61 
than those of alfalfa and red clover, reaching a length of 1.5 mm., 
but in shape resemble closely those of red clover. They are 
flattened rounded triangular with one concave side. 
HISTOLOGY 
StEM.—The epidermal cells are thin-walled, pitted, and longi- 
tudinally elongated, with numerous stomata. The cuticle shows 
longitudinal striations. Occasional hairs both unicellular and 
capitate are present, the warts usually being indistinct. 
Bast.—Conspicuous crystal cells 
are found in the bast just below 
the chlorophyll-bearing cells. 
EAF.—The upper epidermis 
consists of isodiametric cells, avera- 
ging 30 w in diameter, with straight 
thin walls. 
In the mesophyll the cells 
accompanying the bundles contain 
crystals averaging 15 u in length. 
Lower epidermis (fig. 8)—The 
cells are similar to those of the 
upper surface, the walls toward Fic. 8.—Alsike clover (Trifolium 
the leaf margins becoming gently Aybridum): lower epidermis of leat 
wavy. Occasional unicellular (#) With unicellular hair (?), capitate woe 
: 5 (#), and stoma (sto); X160. 
and capitate (#) hairs are present, 
e former being indistinctly warty and arising from a slightly 
thickened epidermal cell. They vary in length up to 800 p. 
Catyx.—The outer and inner epidermis, with sinuous walls, bear 
capitate hairs similar to those on the leaf, also, at the base of the 
lobes and along their margins, unicellular thick-walled hairs with 
occasional indistinct warts. 
Corotta.—The epidermis consists of elongated sinuous-walled 
cells with striated cuticle, papillae being present at the tip of the 
petals 
_ Pericarp.—The epicarp consists of transversely elongated 
slightly sinuous thin-walled cells, scattered stomata, and, especially 
at the margins, capitate hairs. 
