GENUS 95. THISTLE FAMILY. 531 
heads of both tubular and radiate yellow flowers at the summit of a scaly scape, appearing 
before the leaves of the season. Involucre campanulate to cylindric, its Principal bracts in 
a single series, equal, with or without a few shorter outer ones. Receptacle flat, naked. 
Ray-flowers in several series, pistillate, fertile. Disk-flowers perfect, sterile, the corolla 
5-cleft, the style undivided and obtuse, lobed. Achenes of the ray-flowers linear, 5—10-ribbed. 
Pappus copious, of numerous slender roughish We f 
bristles, that of the sterile flowers shorter than ~ 
that of the fertile. [Latin, tussis, cough, for é 
which the plant was a reputed remedy.] 
A monotypic genus of northern Europe and Asia. 
1. Tussilago Farfara L. Coltsfoot. 
Coughwort. Fig. 4594. 
Tussilago Farfara L. Sp. Pl. 865. 1753. 
Scape slender, 3-18’ high, bearing a solitary 
large head at the summit. Leaves nearly orbicu- 
lar, or broadly ovate-reniform, angulately lobed 
and dentate, 3-7’ broad, green and glabrous above, 
persistently white-tomentose beneath; head about 
1’ broad; involucre campanulate; rays bright yel- 
low, numerous, linear. 
In moist soil, on banks and roadsides, Nova Scotia 
and New Brunswick to New Jersey, Pennsylvania 
and Minnesota. Naturalized from Europe. Horse- 
foot. Horse-hoof. Dove-dock. Sow-foot. Colt-herb. 
Hoofs. Cleats. Ass’s-foot. Bull’s-foot. Foal-foot. 
oa Clay-weed. Butter-bur. Dummy-weed. April- 
une. 
96. PETASITES [Tourn.] Mill. Gard. Dict. Abr. Ed. 4. 1754. 
Herbs with perennial thick horizontal rootstocks, broad, basal, petioled leaves, and scaly 
scapes bearing racemose or corymbose heads of tubular or both tubular and radiate, white 
or purplish, often dioecious or subdioecious flowers. Involucre campanulate to cylindric, 
its bracts in 1 series, equal. Receptacle flat, or nearly so, not chaffy. Corolla of pistillate 
flowers very slender, 2-5-toothed, truncate or sometimes with a ray, marginal, or composing 
most of the head; perfect but sterile flowers with a tubular 5-cleft corolla, the style undi- 
vided. Anthers entire or minutely sagittate at the base. Fertile achenes linear, the pappus 
of numerous capillary rough or barbellate bristles. [Greek, a broad-rimmed hat, referring 
to the broad leaves of these plants.] 
About 20 species, north temperate and subarctic. Type species: Tussilago Petasites L. 
Flowers whitish, the pistillate radiate; natives; northern. 
Leaves orbicular, 7—11-cleft nearly to the base. 1. P. palmata. 
Leaves deltoid-reniform, sinuate-lobed and toothed. 2. P. trigonophylia. 
Leaves deltoid-ovate, repand-denticulate. 3. P. sagittata. 
Flowers all rayless, purple; introduced. 4. P. Petasites. 
1. Petasites palmata (Ait.) A. Gray. Pal- 
mate-leaf Sweet Coltsfoot. Fig. 4595. 
Tussilago palmata Ait. Hort. Kew. 2: 188. pl. 2. 1789. 
Nardosmia palmata Hook. Fl. Bor. Am. 1: 308. 1833. 
P. palmata A, Gray, in Brew. & Wats. Bot. Cal.1: 407. 1876. 
Scape very scaly, stout, 6-24’ high. Leaves nearly 
orbicular in outline, 3-12’ broad, deeply 7-11-cleft 
to much beyond the middle, green and glabrous 
above, densely white-tomentose beneath, at least 
when young, sometimes becoming glabrate, the lobes 
oblong or obovate, acute, often somewhat cuneate, 
sharply dentate or incised; heads mostly dioecious, 
corymbose or racemose-corymbose, numerous, 4-6” 
broad; flowers nearly white, fragrant, the marginal 
ones of the pistillate heads radiate. 
In swamps and along streams, Newfoundland to Mas- 
sachusetts, New York, Wisconsin, Minnesota and Alberta. 
Far western plants, formerly included in this species, 
prove to be distinct. April-June. Butter-bur. 
