GENUS 41. 



THISTLE FAMILY. 



i. Gifola germanica (L.) Dumort. Cudweed. Cotton 

 Rose. Herb Impius. Fig. 4389. 



Gnaphalium germanicum L. Sp. PI. 857. 1753. 

 Filago germanica L. Sp. PI. Ed. 2, 1311. 1763. 

 Gifola germanica Dumort. Fl. Belg. 68. 1827. 



Annual, erect, cottony, 4'-i8' high, simple, or branched at 

 the base, very leafy. Leaves sessile, lanceolate, linear, or 

 slightly spatulate, erect or ascending, obtuse or acutish, 3"-i2" 

 long; stem terminated by a sessile dense cluster of heads, 

 usually subtended by several leafy branches terminated by 

 similar clusters and these often again proliferous; heads 12-30 

 in each cluster, many-flowered ; involucre ovoid, light yellow, 

 its bracts mainly acute. 



In dry fields, southern New York and New Jersey to Pennsylva- 

 nia, West Virginia and North Carolina. Old names downweed. 

 hoarwort, owl's-crown, chafeweed, childing cudweed. May-Sept. 



42. PLUCHEA Cass. Bull. Soc. Philom. 1817: 31. 1817. 



Pubescent or glabrous herbs, or some tropical species shrubby, with alternate dentate 

 leaves, and small heads of tubular flowers in terminal corymbose cymes. Involucre ovoid, 

 campanulate, or nearly hemispheric, its bracts appressed, herbaceous, imbricated in several 

 series. Receptacle flat, naked. Outer flowers of the head pistillate, their corollas filiform, 

 3-cleft or dentate at the apex. Central flowers perfect, but mainly sterile, their corollas S-cleft. 

 Anthers sagittate at the base, the auricles caudate. Style of the perfect flowers 2-cleft or 

 undivided. Achenes 4-S-angled. Pappus a single series of capillary scabrous bristles. [Named 

 for the Abbe N. A. Pluche, of Paris.] 



About 35 species, widely distributed in warm and temperate regions. In addition to the follow- 

 ing, 2 or 3 other indigenous species occurs in the southern United States, and two introduced ones 

 have been found in waste places in Florida. Type species : Conyza marilandica Michx. 



Perennial; leaves sessile, cordate, or clasping at the base. i. P.foetida. 



Annual ; leaves, at least those of the stem, petioled. 



Leaves short-petioled ; heads about 3" high ; involucral bracts densely puberulent. 



2. P. camphorata. 

 Leaves slender-petioled ; heads 2"-2^" high; involucral bracts granulose, ciliate. 



3. P.petiolata. 



i. Pluchea foetida (L.) DC. Viscid Marsh 

 Fleabane. Fig. 4390. 



Baccharis foetida L. Sp. PI. 861. 1753. 

 Baccharis viscosa Walt. Fl. Car. 202. 1788. 

 Pluchea bifrons DC. Prodr. 5: 451. 1836. 

 Pluchea foetida DC. Prodr. 5 : 452. 1836. 



Root perennial ; stem simple or sparingly branch- 

 ed at the summit, puberulent and slightly viscid, 

 i4-3 high. Leaves oblong, ovate or ovate-lan- 

 ceolate, closely sessile and more or less cordate- 

 clasping at the base, obtuse or acute at the apex, 

 sharply denticulate, pubescent or puberulent, 2'-4' 

 long, $'-!$' wide, reticulate-veiny; clusters of 

 heads sessile, or stalked, compact, leafy-bracted ; 

 involucre 2$"-3" high, its bracts lanceolate, acute, 

 viscid-puberulent. 



In swamps, southern New Jersey to Florida and 

 Texas, mainly near the coast. Also in the West In- 

 dies. Foetid marsh-fleabane. July-Sept. 



