Part 15

=Dandelion.= Taraxacum officinale Weber. Taraxacum Taraxacum (L.) Karst. Flowers yellow; achenes dull light to dark brown, flattened oblanceolate, thread-like beak two to three times as long as the achene, the stout colored beak 0.5 mm. long. The most conspicuous character of the achenes lies in the barb-like-toothed edges and ridges of each of the similar faces, extending along the upper half. Achene, 3-4 mm. long, having twelve longitudinal ridges, 1.2 mm. wide. Introduced from Europe. Troublesome on thin lawns.

=Salsify. Oyster-Plant.= Tragopogon porrifolius L. Flowers purple; achenes dull light brown, nearly cylindrical; apex tapering, mostly terminating in a slender beak which is often longer than the body of the achene. Achene straight or curved, 10-ribbed, 12-18 mm. long, outermost coarsely roughened by upwardly directed, whitish, scale-like projections. Native of Europe.

=Meadow Salsify. Yellow Goat's Beard.= Tragopogon pratensis L. Flowers yellow; achenes dull, light brown, nearly cylindrical, apex tapering, mostly terminating in a slender beak. Achene straight or curved, 10-ribbed, 12-15 mm. long, the inner ones of the head smooth, the outer-most coarsely roughened by upwardly directed, whitish, scale-like projections. Introduced from Europe.

=American Cocklebur.= Xanthium Canadensis Mill. Achenes or burs reddish brown, oblong, circular in section, two-beaked, about 20 mm. long, covered with stout hooked prickles. Each bur encloses two seeds. Native of this country.

=Spiny Clotbur.= Xanthium spinosum L. Bur oblong, light brown, very slightly flattened, 10-13 mm. long, the beaks weak and small, small hooked prickles 3-4 mm. long, each bur contains two seeds. Introduced from Europe.

=Broad Cocklebur.= Xanthium strumarium L. Bur dark brown, oval, circular in sections 12-22 mm. long, beaks stout, nearly straight, spines about 5 mm. long, surface of burs and base of spines clothed with minute hooked prickles. Naturalized from Europe.

INDEX.

Page

Abutilon, 145

Acalypha, 143

AC-CUM'BENT, leaning or lying upon, applied to cotyledons when the caulicle (radicle) is folded against their contiguous edges, shown as [Symbol: 0== rotated 90 deg. clockwise].

A-CHENE', achenium, a small, dry, one-seeded, indehiscent fruit, likely to be mistaken for a seed.

Achillea, 160

Acnida, 126

A-CU'MIN-ATE, ending in a prolonged tapering point.

Agrimonia, 138

Agrimony, tall hairy, 138

Agrostemma, 128

Agropyron, 110

Aizoaceae, 128

Alfalfa, 140

Allium, 119

Alfilaria, 142

Alsike clover, 141

Alsine, 131

Alyssum, 132

Alyssum, hoary, 133

Amaranth, 126, 127