1170 CARDUACEAE 



gested cymes : leaf-blades ovate to oblong-ovate, 3-6 cm. long, obtuse, manifestly crenate, 

 cordate or subcordate at the base, short-petioled : involucres 3 mm. high : bracts linear- 

 subulate, rather acuminate, finely pubescent : receptacle low-conic : corollas purplish blue : 

 achenes 1.5 mm. long. 



In low grounds, southern Texas and adjacent Mexico. 



5. Conoclinum integrif olium (A. Gray) Small. Similar to C. betonicum in habit, but 

 usually more slender, and much less and more finely pubescent : leaf-blades ovate or rhom- 

 bic-ovate, 2-4 cm. long, rounded at the apex, entire or essentially so, cuneately narrowed 

 with slender petioles : involucres about 4 mm. high : bracts linear-subulate, acuminate : 

 corollas purijlish blue. [Eupatorium betonicum var. inteyrifoliuni A. Gray.] 



In low grounds, southern Texas and adjacent Mexico. 



12. ■WILLUGBAEYA Neck. 



Perennial herbaceous twining vines, with branching stems. Leaves opposite : blades 

 usually of a hastate or deltoid type, slender-petioled. Heads discoid, in corymbose-cymose 

 clusters. Involucres 4-flowered : bracts 4, or rarely 8, nearly equal. Receptacle small, 

 naked. Corollas white or pink, regular. Anthers obtuse and entire at the base. Stigmas 

 elongated, acutish. Achenes 5-angled, truncate. Pappus of one series of many scabrous 

 hair-like bristles. \lSIikania Willd.] The plants flower mainly in summer and fall. 



Involucres less than 4 mm. high. 1. W.heterophylla. 

 Involucres over 4 mm. high. 



Tip of the leaf-blade acute : involucres about 5 mm. high, 2. W. scandens. 



Tip of the leaf-blade obtuse : involucres about 6 mm. high. 3. W. Halei. 



1. Willugbaeya heterophylla Small. Glabrous. Stems several m. long : leaves 

 various, often clustered on sliort branchlets ; blades deltoid to hastate-ovate, 1-3 cm. long, 

 or sometimes smaller, acute or acuminate, entire or repand, cordate ; petioles sometimes 

 longer than the blades : corymbs 1-3 cm. broad : heads rather few : involucres narrow, 

 about 3 mm. high ; bracts linear, obtuse, ribbed : achenes stout, 1-1.5 mm. long, glabrous 

 or nearly so, the faces slightly concave : pappus-bristles 2.5 mm. long. 



In sandy lields, No Name Key, Florida. 



2. Willugbaeya scdndens (L. ) Kuntze. Finely pubescent or nearly glabrous. 

 Stems sometimes densely matted : leaf-blades deltoid-ovate or hastate, acuminate, undulate 

 or angulately lobed, cordate ; petioles often nearly as long as the blades : heads numerous : 

 involucres narrow, about 5 mm. high ; bracts linear, acuminate or apiculate : achenes 

 slender, 2 mm. long, glabrous or nearly so, the faces nearly fiat : pappus-bristles 2.5 mm. 

 long. 



In moist thickets and swamps, Massachusetts to Ontario. Indiana, Florida and Texas. 



3. Willugbaeya Halei Small. Puberulent or glabrate in age. Stems somewhat 

 angled : leaf-blades triangular-hastate, 5-12 cm. long, often acuminate, but blunt, repand- 

 dentate, cordate : corymbs rounded : heads in numerous globular clusters : involucres nar- 

 row, fully 6 mm. high ; bracts linear, acuminate, chaft'y : achenes 4-5 mm. long, sharply 

 angled, the faces concave : pappus-bristles 5 mm. long. 



In low grounds, Louisiana. 



13. TRILISA Cass. 

 Perennial caulescent herbs, with fibrous roots. Leaves alternate : blades various, 

 those of the basal leaves with broad petioles, those of the stem-leaves sessile or clasping. 

 Heads discoid, in thyrsoid or corymbose panicles, 5-10-flowered. Involucres campanulate, 

 peduncled : bracts slightly imbricated, nearly equal in length. Receptacle flat, naked. 

 Corollas purplish or white, regular. Anthers obtuse at the base. Stigmas slender, ob- 

 tuse. Achenes 10-ribbed, but nearly terete. Pappus of 1-2 series of barbellate hair-like 

 bristles. 



Stems viscid-pubescent : heads in thyrsoid panicles : achenes pubescent. 1. T. paniculata. 



Stems glabrous : heads in corymbose" panicles : achenes glandular. 2. T. odoratissima. 



1. Trilisa paniculata (Walt.) Cass. Stems viscid-pubescent, 3-9 dm. tall. Basal 

 leaves 6-30 cm. long ; blades elliptic to almost linear, acute or slightly acuminate : 

 stem-leaves with elliptic or linear-lanceolate, sessile or somewhat clasping blades : involu- 

 cres 4-4.5 nnn. high ; bracts oblong to linear, or commonly slightly broadened upward, 

 obtuse : achenes 2 mm. long, pubescent. 



In damp pine lands, Virginia to Florida. Summer and fall. 



