634 COMPOSITAE 
Leaves very large, broad with smooth margins . . . Arctium 
Leaves armed with prickles. 
Receptacle not bristly nor chaffy . ... . Onopordum 
Receptacle bristly. 
Flowers, “purple © < "0°90, 72) & MP oo. oe) aces 
Flowers yellow .. . 2 us ey fe wy oh Tens 
Leaves lance-shaped or deeply eee not armed with prickles 
ee ee eee Jae Centaurea 
1. VERNONIA, Schreb. 
Coarse erect herbs, with leafy stems and flower heads in diffuse clus- 
ters. Leaves alternate. Heads with tubular flowers only (no rays) ; 
purple, pink or white. Bracts of the involucre overlapping in several 
series. Receptacle naked, flat. Corolla tubular, 5-lobed, regular. Anthers 
narrow-formed at the base, without tails. Aigrette of 2 series, the inner 
series of soft hairy bristles, the outer of scales or stout bristles. 
Some or all of the involucre bracts with bristle-like tips . . . V. noveboracensis 
None of the bracts with bristle-like tips. 
Lower leaves. €gg- or pear-shaped . . « « e« « » « ec co UVa |Siguea 
Lower leaves lance-shaped . . . e's ee! Je cis, ye (ecg feu TEISCE YES 
1. V. noveboracensis, (L.) wild. (Fig. 1, pl. 169.) Iron Weep. 
Plant rather rough, tall (3 to 9 ft. high), with alternate lance-shaped 
leaves with quite low teeth at margins, tapering to a short leaf-stalk. 
Heads numerous, on stems, with overlapping scales and 20 to 30 purple 
tubular (rarely white) flowers. Low grounds, Mass., westward and 
southward. July-Sept. 
2. V. glauca, (L.) Britton. (Fig. 2, pl. 169.) Broap-LrAvep IRon- 
WEED. Plant slender, 2 to 5 ft. high, not hairy or only slightly so. Leaves 
thin, the lower broadly egg-shaped, sharply toothed, acute at apex, 4 to 
7 in. long; the upper leaves narrower and finely toothed. Flower heads 
in a broad loose cluster. Woods, Pennsylvania and southward. Aug.- 
Sept. 
3. V. altissima, Nutt. (Fig. 3, pl. 169.) Tarn IRoN-weep. (V. gi- 
gantea, (Walt.) Britton.) Plant slender, 5 to 10 ft. high, not hairy or 
only slightly so. Leaves thin, lance-shaped, 4 to 12 in. long, finely toothed. 
Flower heads in a broad nearly flat cluster. Moist soil, Pennsylvania and 
southward. July-Sept. 
2. ELEPHANTOPUS, L 
Rough herbs, with alternate or basal leaves and heads of flowers sub- 
tended by large leaf-like bracts. The heads containing few (2 to 5) 
flowers, which are tubular, 5-cleft, with no ray flowers. Aigrette of stout 
bristles. 
1. E. carolinianus, Willd. (Fig. 4, pl. 169.) Exernant’s Foor. Erect, 
1 to 3 ft. high, somewhat hairy. Stem leafy. Leaves oval to inversely 
egg-shaped, thin, narrowing to a leaf-stalk. Flowers purple, bracts large. 
Southern part of our area. Aug.-Sept. 
2. E. nudatus, A. Gray. (Fig. 5, pl. 169.) Smoornisn ELEPHANT’s- 
roor. Stem with one or two small leaves or more. Basal leaves oblong 
or inversely lance-shaped. Delaware and southward. Aug.-Sept, 
