850 COMPOSITAE (COMPOSITE FAMILY) 



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

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

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

 World.) 



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



14. A. ABSINTHIUM L. (WORMWOOD.) Rather shrubby, 6-9 din. high, 

 silky-hoary; leaves 2-S-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 (1.5-5 dm. high), in tufts, slightly woody at the 

 base, white-silky; leaves p innately parted and 'A-5-cleft, the divisions narrowly 

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

 and westw. 



74. TUSSILAGO [Tourn.] 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., O., and 

 Minn. (Nat. from Eu.) 



75. PETASITES [Tourn.] 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 ireracroj, 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 5-7-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. 



*- t- 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., a. to Minn., Col., etc. 

 May, June. 



* * Ligules none ; flowers purplish. 



4. P. VULGARIS 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.) 



