COMPOSITE FAMILY. 229 



77. TARAXACUM. Head of very many yellow flowers on a slender, hollow, and wholly 



naked scape. Involucre double, the inner of numerous narrow scales in a single 

 row, the outer of short loose scales. Akenes terete or spindle-shaped, strongly 

 ribbed and tubercled on the ribs, much shorter than its slender beak which elevates 

 at maturity the soft and white pappus. (Lessons, Fig. 384.) 



78. CHONDRILLA. Heads few-flowered, small, yellow. Involucre cylindrical, of several 



very narrow equal scales, and a row of small bracts at the base. Akene terete, sev- 

 eral-ribbed, rough above but smooth below. Pappus bright white. Wand-like herbs. 



79. LACTUCA. Heads of several variously colored flowers. Involucre of several lanceo- 



late or ovate imbricated scales of unequal length. Akenes flat, abruptly contracted 

 into the beak or neck which elevates the very white soft pappus. Stems leafy. 

 +- +- Akenes beakless. 



80. SONCHUS. Involucre as in the last, or with narrow and more equal scales, and tumid 



at base. Flowers yellow. Akene flat and short, without a beak to support its very 

 soft whi*e pappus. Stems branching and leafy. (Lessons, Fig. 883.) 



1. VERNONIA, IRONWEED. (Named for a' Wm. Vernon, of Eng- 

 land, who traveled in this country.) Flowers autumn. ^ 



* Leaves slightly or not at all scabrous, not revolute. 



V. Noveboracensis, Willd. COMMON IRONWEED. Near the coast 

 and along rivers W. ; 3-6 high, with lanceolate serrate leaves, crowded 

 along the whole height of the stem ; heads in a broad cyme ; scales of 

 involucre with slender awl-shaped or awn-like tips ; akene lightly hairy. 



V. altissima, Nutt. Tall ; leaves lanceolate ; cyme loose ; scales close, 

 obtuse or simply mucronate ; akene slightly hairy. Penn., W. and S. 



V. fasciculata, Michx. Scales of involucre blunt and pointless, except 

 perhaps some of the lowest ; akene smooth. Ohio, W. and S. 

 * * Leaves scabrous above, often revolute. 



V. angustif6lia, Michx. Slender, l-3 high ; leaves filiform to linear- 

 lanceolate ; akenes minutely hirsute. N. C., S. and W. 



2. PIQTJERIA. (Named for a Spanish botanist, A. Piquerio.*). 



P. trinervia, Cav. Mexico ; cult, for winter-blooming ; smooth, 2-3 

 high (also a dwarfer form), branched, with lance-oblong, 3-nerved, spar- 

 ingly serrate leaves, and loose panicled corymbs of very small white- 

 flowered heads ; much used in dressing larger cut flowers. A form with 

 white- edged leaves is used for edgings. In gardens often known as 

 STEVIA SERRATA. 2/ 



3. SCLEROLEPIS. (Greek : hard scale, referring to the pappus.) 11 

 S. verticillata, Cass. Stem simple, rooting in water at the base ; 



leaves linear and entire, small, in whorls of 4-6 ; flowers rose-purple or 

 flesh-colored in a small terminal peduncled cluster. Pine barrens, N. J., S. 



4. AGERATUM. (Greek : not growing old, probably applied originally 

 to some sort of Everlasting.) 



A. conyzoldes, Linn. Soft-downy, 2-3 high; ovate or somewhat 

 heart-shaped petioled leaves ; corymbed heads of azure-blue flowers, 

 produced all summer and autumn. Known in gardens as A. MEXICANUM. 

 Tropical Amer.; sparingly nat. S. 



5. MIKANIA, CLIMBING HEMP WEED. (A Bohemian botanist, 

 Prof. Mikan.) 



M. scandens, Willd. Rather handsome plant, climbing over bushes 

 in low grounds, N. Eng. S. and W.; leaves triangular-heart-shaped or 

 halberd-shaped ; heads small, of purplish flowers, in summer. 2 



