THE TlIIsrLK KAMILV. 



3«7 



I 



I 



which produces no pappus. The scales of its receptacles are " chaffy." 

 smaller leaf-cup we find in shaded, moist places. 



P. Uvedalia, yellow, or large-flowered Icaf-cup, or yellow bear's f. 

 decidedly a more showy species than the preceding one, as its ray-flov.' 

 large and of a lively, bright shade of yellow. The cup-shaped irr. 

 with ovate-oblong bracts shows also that they are ciliate about their margins, 

 a feature again noticed about the leaves. Those of the lower stem arc 

 broadly-ovate with a strong inclination towards being angular and lobcd. 

 and attain sometimes enormous proportions. The plant exhales a peculiar, 

 resinous odour, and late in the season the people collect its heavy root. 



P. hnngdta, the third species of Polymnia known in North America, has 

 decidedly the prettiest leaves of them all, they being long-petioled and pin- 

 nately lobed, or divided often to within a quarter of an inch of the midrib. 

 or the upper ones becoming deltoid-ovate. They are besides smooth and. 

 when dried, as thin and crisp as tissue paper. The light-yellow flower-heads 

 with their bell-shaped disk-flowers are not at all conspicuous, and. as has 

 been mentioned, the achenes are five times ribbed. 



PRAIRIE DOCK OR BURDOCK. RESIN PLANT. 



{^Plate CLXXII.) 



SilpJiiiDU tcrcbi)itJii)idLtuni . 



FAMILY COLOUR ODOUR RANGE TIME OF BLOOM 



Thistle. Orange-yelloiu. Scetitless. Loiu'siaiia ami Georg;ia I ul)-Srftftnhrr. 



northward a nd westward. 



Flower-heads : growing in terminal, corymbose clusters and having both r-idiatc 

 and tubular flowers inclosed within an involucre of ovate, imbricated scales. 

 A'^zj'J- ; twelve to twenty, long-oblong, slightly notched at the apex. Disk-Jiowers: 

 very numerous; perfect; sterile. Achenes: obovate; flattened; two-tootlied. Ltavts : 

 large ; from the base with long, grooved ])etioles; oval, or ovate, bluntly pointed 

 or rounded at the apex and tapering into petioles at the base, or being deeply cor- 

 date, sharply serrate, or remotely dentate; coarse ; thick ; rough. Slfm-Uares : 

 small; scale-like. Stems: four to'ten feet high ; finely grooved ; smooth. 



When through stony ground and often in dry woods, one sees a plant with 

 such flower-heads as are shown in the illustration of this one. and then tinds 

 it has very large and coarse basal leaves, there is a rather good chance that 

 it may be the prairie dock, although the perplexities arising among the com- 

 posites are indeed great. The whole genus, however, is possessed of a 

 resinous juice, which, especially of the species Silphium laciniatum, is ob- 

 tained and considerably used by country people. 



S. laciniatum, pilot, polar or compass-plant, resin or turpentine weed, is 

 familiar from the prairies of Ohio southward to Alabama and Texas. It is 

 very peculiar-looking, coarse, hispid and hairy, with alternate leaves deeply 

 and pinnately divided and petioles that are very long. The w^..!-- mIoh, 



