Contributions to Western Botany. 71 
faint traces of the markings of A. anceps outer membrane, and 
the sepals are constricted over the ovary 
Onions having meshes like grass-nerves are A. heematochi- 
ton, validam, cernuum, lacunosum, stellatum, and _ probably 
scaposum. 
Onions having branched ribs are A. Parryi, Lemmoni, atro- 
rubens, parvum, Douglasii,ambiguum, stellatum, macrum, cam- 
panulatum and bisceptruin. 
Such species as A. Parryi, atrorubens, decipiens, fimbriatum, 
and perhaps cristatum are probably without special markings, 
the markings given being those of the outer coat, but these are 
serviceable in determining the species because of their relative 
size. 
The markings of A. ambiguum to A. obtusum are possibly 
those of the outer coat only though they are unusually strong 
for such markings. There are no other meshes. 
The markings of A. serratum, attenuifolium, hyalinum, and 
peninsulare are the longest in the genus, being from 8-16” long, 
and rarely over 1” wide, under the same enlargement. The 
markings of A. Bolanderi, madidum, and collinum are similar 
but run from 4-8’* long and 3-1” wide, under the same enlarge- 
ment. The walls of the meshes of A. attenuifolium, hyalinum 
and Bolanderi are very delicate and thin, the most so of any 
special markings of our onions, though equaled in fineness by 
the markings of the outer coats of most onions, these latter 
coats are very thin and have meshes which are rectangular or 
nearly so except in A. acuminatum and Bolanderi which have 
very much distorted meshes (for which see the figures). 
A. acuminatum Hooker. Watson represents this species as 
having the walls of the meshes composed of 3 lines, but this is 
an optical illusion, the walls are solid, wide, apparently flat on 
the top but really beaded; the outer coat is yellowish and rigid; 
Sepals purple-tipped, always paler below, rigid, carinate in shorn 
filaments subalate; bulbs always clove to the surface. 
