188 DICOTYLEDONOUS. 



merous, covered externally with a glandular pubescence. Seeds angular, 

 striate. Receptacle flat. 



Pale purple. % April— May. Mid. and upper Dist. of Car. & Ga. 1-2 ft. 



2. M. AxGUf-TiFOLiA. Stem erect, branching, angular, glabrous, or slight- 

 ly pubescent towards the summit. Leaves long, narrow-lanceolate, glabrous, 

 the upper ones linear. Flowers solitary, terminal ; involucre with numerous 

 subulate leaves. Corolla pubescent without. Seed angular. 

 Pale purple. Tj. Maj- — June. In pine barrens. 1-2 ft. 



Gexus XLII. chrysanthemum. 



Involucre imbricate, wiih subulate leaves ; ray florets pistil- 

 late, those of the disk perfect ; receptacle naked ; pappus none. 



1. C. Leucaxthemum. Stem erect, somewhat branched, glabrous, or very 

 slightly pubescent. Leaves sesi-ile, amp[exicaule, lanceolate, dentate towards 

 the base, or sometimes nearly pinnatifid. Flowers solitary; involucre gla- 

 brous, v^ith the margins of tlie leaves membranaceous. Seed furrowed. 

 White. %. May— July. Close soils. Introduced. 1-2 ft. 



Gekus XLIII. HELEMUM. 



Involucre gamosepalous, many parted ; florets of the ray 

 pisiillate. of the disk perfect. Pappus chaff*}', 5-awned. 

 Receptacle globose, naked. 



1, H. A' ToixALE. Stem erect, branching towards the summit, glabrous, 

 winged by the decurrent leaves. Leaves sessile, alternate, lanceolate, doubly 

 serrate, glabrous. Flowers in small corymbs : involucre 8-parted, with subulate 

 segments, longer than the disk : ray florets about 10, 3-tooihed at the summit. 

 Seed angular, larger at the summit; scales of the pappus lacerate, mucronate. 



Yellow. % October — Nov. In wet soils. 2-3 ft- 



2. H. QuADRiDEXTATUM. Stem erect, pubescent, slightly winged, by the 

 decurrent leaves. Zeares narrow-lanceolate, entire, pubescent. Flowers sol- 

 itary and terminal ; ray florets obovate, 3-4-toothed. Seeds hispid; pappus 

 consistins of 6 mucronate scales ; receptacle oblong 



Yellow. % Sept.— Oct. Swampy lands. 2-3 ft. 



Gexts XLIV. ACMELLA. 



Involucre consisting of 12 leaves, arranged in a double se- 

 ries, pubescent, equal ; florets of the ray pistillate, of the 

 disk perfect. Seed quadrangular, compressed. Receptacle 

 chaff}', with yellow scales. 



1. A. Repens. Stem procumbent, rooting at the lower joints, pubescent. 

 Leaves opposite, ovate-lanceolate, attenuate at the base, slightly pubescent. 

 Flowers solitary, on axillary and terminal peduncles. Leaves of the involu- 

 cre ovate-lanceolate, acute ; ray florets about 12. Seed oblong, naked, trun- 

 cate at the summit. 



Yellow. % Sept.— Oct. Wet soils. 1-2 ft. 



Gents XLV. HELIOPSIS. 



Involucre imbricate, many leaved ; ray florets pistillate, 

 those of the disk perfect. Receptacle conic. Seed quadran- 

 gular. Pappus wanting. 



