COMPOSITE FAMILY. 229 



TT. TAEAXACUM. 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. 884.) 



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. SONOHUS. 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 white pappus. Stems branching and leafy. (Lessons, Fig. 383.) 



1. VEHNONIA, 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. Noveborac^nsis, 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. altf ssima, 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. angustif61ia, Michx. Slender, l°-3° high ; leaves filiform to linear- 

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



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



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

 high (also a dwarf er 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, 21 



3. SCLEROLEFIS. (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. (J) 



5. MIKANIA, CLIMBING HEMPWEED. (A Bohemian botanist, 

 Prof. Mikan.) 



M. scandenB, Willd. Eather 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. % 



