690 COMPOSITAE 
not marginal with stamens and pistils, fertile. Fruit 5-angled, aigrette 
none, or a low border. 
1. T. vulgare, L. (Fig. 1, pl. 194.) Tansy. Stem simple, 1 to 3 
ft. high. Leaves divided pinnately, the lobes deeply toothed. Heads 
numerous, rounded, yellow. A strongly aromatic plant growing in patches. 
July-Sept. 
2. T. huronense, Nutt. Lake Huron Tansy. Plant silky with soft 
hairs; heads fewer. Otherwise similar to No. 1. Extreme northern part 
of our area. July-Sept. 
42. ARTEMISIA, L. 
Bitter odorous herbs or shrubs with alternate leaves and commonly 
with small nodding greenish or yellowish heads without rays, in narrow 
elongated clusters. Receptacles small, flat, naked. Involucre of overlap- 
ping dry scales. Marginal florets pistil-bearing or sometimes with pistils 
and stamens. Central florets perfect. Fruit inversely egg-shaped, without 
an aigrette. 
Plants not white woolly 
Receptacle Naked; Disk Flowers Sterile 
1. A. canadensis, Michx. Canapa Wormwoop. Heads } in. broad, in 
a narrow interrupted spike-like cluster. Stem downy, straight, simple or 
branched. Leaves slashed into linear lobes, the lower ones on leaf-stalks. 
Roeky soil, mostly in the northern part of our area. July-Aug. 
2. A. caudata, Michx. (Fig. 6, pl. 194.) Witp Wormwoop. Heads 
1/12 in. broad, in a broad rather loose elongated or pyramidal cluster 
comprising large numbers of heads. Stem slender, smooth, 2 to 6 ft. 
high. Leaves deeply divided into linear segments, the lower on leaf- 
stalks. Heads nearly erect. Sandy soil, especially on sea beaches. July- 
Sept. 
Receptacle Naked or Hairy; Disk Flowers Fertile 
3. A. absinthium, L. (Fig. 2. pl. 194.) AssintH. Common WoRrM- 
woop. Leaves deeply divided into fan-like segments, downy. Heads yel- 
low, drooping. Stem angular, branched, Waste places. Naturalized. 
July-Oct. 
4. A, Abrotanum, L. Sournernwoop. Shrub. Stems woody, 
branched. Leaves in fine thready segments. Flowers numerous, nodding, 
yellow. Well known as an aromatic garden shrub. Escaped and natu- 
ralized in places. 
5. A. annua, L. Annuat Wormwoop. Annual herb. An introduced 
species, smooth, much branched, heads drooping. Leaves thrice divided. 
A weed in waste places. 
Plants woolly white 
6. A. stelleriana, Bess. (Vig. 3, pl. 194.) Bracn Wormwoop. 
Perennial, densely white-silky. Stem 1 to 2 ft. high, bushy. Leaves egg- 
shaped or spatula-shaped, deeply lobed, 1 to 4 in. long. Heads inversely 
cone-shaped, } in. broad, not drooping. Sandy sea beaches, July-Aug. 
7. A. vulgaris, L. (Fig. 4, pl. 194.) Common Muewort. Perennial. 
Branches and under side of leaves wlite woolly. Leaves 1 to 44 in. long, 
