850 coMPOSiTAE (composite family) 



13. A. Annua L. Much branched, very sweet-scented; leaves 2-pinnately 

 divided, the oblong segments deeply pinnatifid ; heads small, in a loose ample 

 panicle. — Waste places, etc., throughout, locally a bad weed. (Nat. from Old 

 World.) 



§ 3. Beceptacle hairy ; flowers all fertile, the marginal ones pistillate. 



14. A. Absinthium L. (Wormwood.) Rather shrubby, 6-9 dm. high, 

 silky-hoary; leaves 2-3-pinnately parted ; lobes lanceolate ; heads hemispherical, 

 panicled. — Roadsides, dry banks, etc., thoroughly established and common, 

 e. Can. and n. N. E.; elsewhere local. (Nat. from Eu.) 



15. A. frigida Willd. Low (L5-5 dm. high), in tufts, slightly woody at the 

 base, white-silky; leaves p innately parted and S-o-cleft, the divisions narrowly 

 linear ; heads globose, racemose. — Dry hills and rocks, Sask. to Minn., w. Tex., 

 and westw. 



74. TUSSILAGO [Toum.] L. Coltsfoot 



Head many-flowered ; ray-flowers in several rows, narrowly ligulate, pistil- 

 late, fertile ; disk-flowers with undivided style, sterile. Involucre nearly simple. 

 Receptacle flat. Achenes slender-cylindric or prismatic ; pappus copious, soft, 

 and capillary. — Low perennial, with horizontal creeping rootstocks, sending up 

 scaly scapes in early spring, bearing a single head, and producing rounded- 

 heart-shaped angled or toothed leaves later in the season, woolly when young. 

 Flowers yellow. (Name from tussis, a cough, for which the plant is a reputed 

 remedy.) 



1. T. Farfara L. — Wet places and along brooks, e. Que. to Pa., 0., and 

 Minn. (Nat. from Eu.) 



75. PETASITES [Toum.] HilL Sweet Coltsfoot 



Heads many-flowered, somewhat dioecious ; in the substerile plant with a 

 single row of ligulate pistillate ray-flowers, and many tubular sterile ones in 

 the disk ; in the fertile plant wholly or chiefly of pistillate flowers, tubular or 

 distinctly ligulate. Otherwise as Tussilago. — Perennial woolly herbs, the leaves 

 all from the rootstock, the scape with sheathing scaly bracts, bearing heads of 

 purplish or whitish fragrant flowers in a corymb. (The Greek name for the 

 Coltsfoot, from, ir^raaos, a broad-brimmed hat, on account of its large leaves.) 



* Pistillate flowers ligulate ; flowers whitish. 



-t- Leaves deeply lobed. 



1. P. palmatus (Ait.) Gray, Leaves rounded, somewhat kidney-form, pal- 

 mately and very deeply o-7-lobed, the lobes toothed and cut. — Woods, swamps, 

 and recent clearings. Lab., to Alb., s. to e. Mass., w. Ct., N. Y., Mich., Wise, and 

 Minn. Apr.-June. — Full-grown leaves 1-2.5 dm. broad. 



+- H- Leaves shallowly or not at all lobed. 



2. P. trigonophyllus Greene. Leaves from broadly cordate-deltoid to sub- 

 orbicular, closely invested beneath with dense white tomentum, the 7-11 shal- 

 low lobes more or less sharply toothed, in maturity 0.5-1.5 dm. broad. — Wet 

 meadows, local, Gaspe Co., Que., Sask., and n. Minn. May. . 



3. P. sagittatus (Pursh) Gray. Leaves deltoid-oblong to reniform-hastate, 

 acute or obtuse, repand-dentate, very white-tomentose beneath, when fully 

 grown 1.7-2.5 dm. broad. — Cold swamps. Lab. to B. C, s. to Minn., Col., etc. 

 May June. 



* * Ligules none ; flowers purplish. 



4. P. vulgXris Hill. (Butterbur.) Rootstock very stout; leaves round- 

 cordate, angulate-dentate and denticulate. — Waste or cultivated ground, e. Mass. 

 and e. Pa. Apr., May. (Nat. from Eu.!) 



