1920] Wiegand,—Eupatorium purpureum and its Allies 67 
crisp-puberulent. Scattered specimens of the typical form have nar- 
row leaves with fine crénate serrations resembling those of E. pur- 
pureum, a variation the significance of which is not understood but 
which is probably ecological. The florets vary considerably in num- 
ber, due apparently in some cases at least to local conditions. Among 
the specimens examined the number of florets ran as follows: 1 
with 7 florets, 2 with 8 florets, 10 with 9 florets, 12 with 10 florets, 
12 with 11 florets, 30 with 12 florets, 17 with 13 florets, 10 with 14 
florets, 7 with 15 florets, 1 with 16 florets, 3 with 17 florets, 1 with 
18 florets, 1 with 19 florets, 0 with 20 florets, and 1 with 21 florets. 
The leaves in the whorls fluctuate within narrow limits. 'The num- 
ber counted ran as follows: 1 with 2 leaves (starved specimen), 7 
with 3 leaves, 55 with 4 leaves, 54 with 5 leaves, and 2 with 6 leaves. 
3. E. PuRPUREUM L. Sp. Pl. ed. 1, ii. 838 (1753) as to synonomy 
under g, which in this case determines the type. E. trifoliatum L. 
Sp. Pl. ed. 1, ii. 837 (1753), placed under E. purpureum by T. & G. 
in 1841. E. americanum Hill, Brit. Herb. 453 (1756). ? E. purpureum 
y angustifolium T. & G. Fl. N. Amer. ii. 82 (1841). E. fistulosum 
Barrett, Eupat. verticillate (1841), see also Wood's Class Book, 
ed. 2, 314 (1847).—Stems normally unspeckled, occasionally mottled, 
uniformly suffused with purple and not darker at the nodes, plainly 
glaucous, glabrous, hollow: leaves in 4's-6's, very rarely in 7's, 
elliptic-lanceolate, acuminate, tapering gradually to the nearly sessile 
base, regularly and finely crenate-serrate, scarcely rugose, above 
glabrous, beneath atomiferous and sparingly fine-puberulent on 
the veins only, or commonly almost glabrous; the veins numerous, 
spreading, regularly decreasing toward base and apex of the leaf; 
inflorescence crisp-pubescent, convex, often hemispherical, when 
well developed large and loose with the lower branches divaricate 
or horizontal: heads purple, narrowly cylindrical, 6-7 (rarely 5 
or 8)-flowered: bracts of the involucre mostly obtuse: corolla 3.5- 
4.8 mm. long, slightly or not at all exserted: achenes 3.2-4.5 mm. 
long.—Low fields and the borders of thickets, if not too wet, in 
rich sandy and gravelly scarcely calcareous soils: southern Maine 
to Rhode Island, Florida, Texas and Oklahoma, and from eastern 
Kentucky, and West Virginia through western Pennsylvania to 
Ohio. Matne: Cape Elizabeth, 1911, M. L. Fernald; Biddeford 
Pool, 1900, G. G. Kennedy. MassAcnHusETTS: Concord, E. S. Hoar; 
Milton, 1899, G. G. Kennedy; East Sandwich, 1919, Fernald & Long, 
no. 19168; Deerfield, 1908, M. A. Day, no. 62. Ruopr IsrAND: 
Providence, G. Thurber. Connecticut: Pomfret, 1910, Sarah R. 
Armington; Gully Brook, Hartford, 1907, A. W. Driggs; Ledyard, 
1901, C. B. Graves, no. 234. Maryann: Ellicott City, 1916, G. 
