170 



ORDER LXIV. COMPOSITE COMPOSITE-FAMILY. 



receptacle. An ill-scented plant, 1 ft. high, with dark-green, very finely dis- 

 sected leaves. Naturalized, and common in road-sides and waste places. June. 

 Sep. 



24. ACHILLEA. 



Heads many-flowered. Rays 5 10, pistillate. Involucre 

 with imbricate, unequal scales. Receptacle flat, chaffy. Pappus 

 none. Per. 



1. A. millefolium. 



Yarrow. 



Stem erect, furrowed, branching above; leaves alternate, bi-pinnately 

 divided, segments linear, toothed or lobed, mucronate ; heads small, numerous, 

 in dense, flat, terminal corymbs ; rays about 5, short, white (sometimes rose- 

 color) ; involucre furrowed, oblong. A common plant, with a pungent and 

 somewhat agreeable odor; 1 ft, high ; in fields and pastures. June Aug. 



25. LEUCANTHEMUM. 



Heads many -flowered. Rays numerous, pistillate. Involucre 

 depressed, flattish ; scales imbricate with scarious margins. Re- 

 ceptacle naked, flat. Achenia striate. Pappus none. Per. 



1. L. vulgare. 



Ox-eye Daisy. 



Stem erect, simple, or sparingly branched, furrowed. Leaves few and 

 rather small, cut- pinnatifid, incised at base; radical ones spatulate, petiolate ; 

 upper ones lanceolate, more or less clasping at base ; heads large, solitary, on 

 long, naked, furrowed peduncles ; rays white ; disk yellow ; involucre-scales 

 with brownish margins. A common and troublesome weed with showy heads. 

 Introduced. July Sep. 



26. PYRfcTHRUM. 



Heads many-flowered. Involucre hemispherical. Scales im- 

 bricate, with membraneous margins. Receptacle naked. Pap- 

 pus reduced to a membraneous border, crowning the achenia. 

 Per. 



1. P. parthenium. Feverfew. 



Stem erect, branching ; leaves alternate, petiolate, tri-pinnately divided ; seg- 

 ments ovate, incised ; heads numerous, corymbosely arranged ; involucre pubes- 

 cent Common in cultivation, and admired for its pure white flowers, which 

 last for some time ; often double. 



27. CHRYSANTHEMUM. 



Heads many-flowered. Involucre hemispherical. Scales im- 

 bricate, with membraneous margins. Receptacle naked. Pap- 

 pus none. Per. 



1. C. coronarium. Grecian Chrysanthemum. 



Stem erect, smooth, branching; leaves alternate, bi-pinnatifld, clasping, 

 acute, broadest near the summit; heads large, terminal, solitary. A garden an- 

 nual. Flowers double in cultivation. Aug. 



2. C. carinatum. Three-colored Clirysanthemum. 



Stem erect, branching; leaves bi-pinnate, fleshy, smooth; heads large, 

 Bhowy ; disk purple; rays white, yellow at base, or entirely yellow ; involucre- 

 scales carinate. A garden annual. July Oct. 



3. C. Sinense. Chinese Chrysanthemum. 



Stem erect, branching ; leaves sinuate-pinnatifid, toothed, coriaceous, glau- 

 cous, petiolate; rays very long, and of lilac, yellow, purple and reddish brown, 

 to a pure and vivid white. A beautiful plant, cultivated in pots, and in 

 sheltered places in the open air. The varieties are almost endless. 



28. COREOPSIS. 



Heads many-flowered. Rays about 8; neutral. Involucre 

 double. Each series 6 10 leaved. Receptacle flat and chaffy. 

 Achenia compressed, emarginate, 2-awned. 



1. C. tinctoria. Coreopsis. 



Smooth; stem erect, branching; radical leaves somewhat bi-pinnate, seg- 

 ments oval, entire ; cauline ones somewhat pinnate, with linear segments ; 

 heads large, numerous, brilliant ; rays bright yellow, brownish purple at base ; 

 achenia smooth. A beautiful garden annual, 13 ft high. Very common in 

 cultivation, with elegant foliage, and numerous very brilliant flowers. All 

 summer. 



29. BiDENS. 



Heads many-flowered. Rays neutral, sometimes inconspicu- 

 ous, or wanting. Involucre double. Outer series large and 



foliaceous. Receptacle chaffy, flat. Achenia compressed, o- 

 slender and 4-sided, armed with 2 4 rigid, persistent awn, 

 which are rough backwards. 



An. 



1. B. frondosa. 



Beggar Ticks. 



Smooth, or slightly pubescent; stem erect, tall, with spreading branches 

 leaves pinnately 3 5-parted, segments lanceolate, acuminate, serrate, mostly 

 petiolate ; leaflets of the outer involucre much longer than the flower, ciliateat 

 base ; heads discoid ; achenia flat, cuneate-obovate, 2-awncd, with rough mar- 

 gins. A common and extremely troublesome weed, in moist, cultivated grounds, 

 and waste places ; the achenia when mature clinging by their awns to every 

 thing that passes them. July Sep. An. 



2. B. connata. 



Burr-Marigold. 



Stem erect, with 4 furrows and opposite branches ; leaves lanceolate, op- 

 posite, acuminate, sharply serrate, tapering into margined, somev/hat connate 

 petioles ; lower ones often 3-parted, with the lateral segments decurrent ; heads 

 solitary, discoid; outer scales of the involucre foliaceous, longer than the 

 flower; achenia flat, narrowly cnneate, with awns. A common species, 1 2 

 ft high, in wet grounds. Aug. Sep. An. 



3. B. cernua. 



Nodding Burr-Marigold. 



Mostly smooth ; stem terete, with the branches opposite ; leaves lanceolate, 

 unequally serrate, slightly connate ; heads nodding, discoid, or with a iVw, 

 short, yellow rays ; leaflets of the outer involucre longer than the head ; ache- 

 nia wedge-obovate, armed with 4 awns. A common species, 12 ft high, 

 growing in swamps and ditches. Aug. Sept. An. 



4. B. chrysanthemoides. Large-flowered 



Burr Marigold. 



Smooth; stem erect, or decumbent; leaves lanceolate, attenuate at each 

 end, connate at base, with regular and even serratures ; heads erect or nodding, 

 radiate ; rays large, conspicuous, bright yellow ; leaflets of the outer involucre 

 mostly shorter than the rays ; achenia cuneate with 2 4 awns. A common 

 and showy plant, growing 6' 18', in swamps and ditches. Sept. Oct. An. 



30. SENECIO. 



Heads many-flowered, either discoid, with tubular, perfect 

 flowers, or radiate, with pistillate rays. Involucre-scales mostly 

 in a single row. Receptacle flat, naked. Pappus simple, capil- 

 lary, copious. Leaves alternate. 



1. S. vulgaris. Common Groundsel. 



Stem erect, branching, angular, mostly smooth ; leaves pinnatifid, toothed, 

 clasping; radical ones petiolate; heads discoid, terminal, yellow, in loose 

 corymbs, nodding. A common weed in waste grounds, 15' high, blooming the 

 whole season. An. 



2. S. aureus. 



Golden Senecio. 



Mostly smooth ; stem furrowed, erect, nearly simple ; radical leaves undi- 

 vided and roundish, mostly cordate, crenate, on long petioles ; lower cauline 

 ones lyrate ; upper lanceolate, pinnatifid, sessile or somewhat clasping ; heads 

 large, showy, with golden-yellow rays, somewhat umbellate, in flat, terminal 

 corymbs ; involucre-scales linear, acute. A very handsome and variable plat*, 

 10' 20' high ; common in meadows and damp thickets. 



The most marked varieties are 1. obovata, radical leaves orbicular-obo- 

 vate; found in drier grounds than the common form. 2. Balsamitop, radical 

 leaves oblong or lanceolate, tapering at base to a petiole. In rocky places. 

 May June. Per. 



31. ARTEMfSIA. 



Heads discoid, few, or many-flowered. Flowers all tubular ; 

 marginal ones usually pistillate, sometimes perfect ; the rest per- 

 fect. Involucre-scales imbricate, dry and scarious on the mar- 

 gins. Receptacle flat, naked, or slightly hairy. Achenia with a 

 small disk at summit. Pappus none. 



1. A. caudata. Slender-leaved Wormwood. 



Smooth ; stem straight, herbaceous ; radical and lower leaves bi- or tripin- 

 nately-parted ; upper ones pinnately-parted ; segments filiform, alternate ; heads 

 small, subglobose, pedicellate, erect, racemose, in a long, terminal panicle ; outer 

 scales of the involucre ovate, inner ones oval. Stem 2 5 ft high. Common 

 near the sea-ooast, from N. II. southward Sept. Bien. 



2. A. Abrotanum. Southernwood. 



Stem erect, shrubby; lower leaves bipinnately-parted ; upper ones pinnate 



