r BUCKWHEAT FAMILY. 287 



. CELOSIA, COCKSCOMB. (Name in Greek means dried, aUuding to 

 the scarious bracts.) PI. summer. ® 



C. crist^ta, Common C. of the gardens, from India, in various usually 

 onstrous forms, the showy flower-crests crimson-red, sometimes rose-colored 

 How, or white. ' 



GOMFHBENA. (Ancient name of an Amaranth.) Fl. summer. 

 Or. glob6sa, Globe Amakanth or Bachelor's-button. Cult, from 

 dia : low, branching, pubescent, with oblong nearly sessile leaves, and dense 

 uud heads crimson, rose-color, or white. 



95. POLTGONACE^, BUCKWHEAT FAMILY. 



Known by the alternate entire leaves having stipules in the form 



■ scarious or membranous sheaths at the strongly marked usually 

 mid joints of the stem. Flowers mostly perfect, on jointed pedi- 

 Is, with green or colored 4 — 6-parted usually persistent or wither- 

 g calyx, 4-9 stamens on its base, 2 or 3 stigmas, 1-celled ovary 

 ith a single ovule rising from its base (Lessons, p. 110, fig. 342), 

 rming an akene or nutlet. Embryo mostly on the outside of 

 ealy albumen, the radicle pointing to the apex of the fruit. 

 Ekiogonum differs in having no obvious stipules, and the 

 iwers from a cup-shaped involucre. There are a few species 



the genus S. and S. W., and many near and beyond the Rocky 

 fountains. 



\ 1. Cahps of 5, rarely 4, more or less petal-like similar sepals, erect after fiawering. 



■ POLYGONUM. Flowers in racemes, spikes, or else in the axils of the leaves. 



Akene either lenticular when there are 2 stigmas, or triangular when there 

 are 3. Embryo curved round one side of the albumen: cotyledonfl narrow. 

 FAGOPYEUM. Differs from one section of Polygonum mainly in having an 

 embryo in the centre of the albumen, which is divided into 2 parts by the 

 very broad leaf-like cotyledons. The triangular akene longer thMi the calyx. 



§ 2. Calyx of 6 sepah often of two sorts : Styles 3. 



EHEUM. Sepals all similar, petal-like, withering-j)ersistent imdemeath the 

 3-winged fruit. Stigmas capitate or wedge-shaped^ Stamens 9. 



EUMEX. Sepals of 2 sorts ; the 3 outer ones herbaceous and at length spread- 

 ing; the alternate inner 3 larger, somewhat colored, enlarging after flowering, 

 becoming veiny and dry, often bearing a grain-like tubercle on the back, and 

 convergent over the 3-angled akene. Stigmas a hairy tuft. Stamens 6. 



POLI^GON'UM, KNOTWEED, JOINTWEED. (The name in Greek 

 neans many-jointed. ) Chiefly weeds ; some with rather showy flowers ; the 

 bllowing are the commonest : fl. late summer and autumn. 



i 1. Flowers along the stem, nearly sessile in the axils of the aimost sessile linear or 

 oblong leaves, small, greenish'^hite : sheaths scarious, usually cleft or torn 

 and fringed. ® 

 ?. avieuliire, Knot-grass, Goose-grass, or Dooeweed. Prostrat* 

 spreading and variable low weed, with pale lanceolate or oblong leaves, 

 imonly 5 stamens, and dull 3-sided akene enclosed in the calyx. , Var. 

 SOTCM, has more upright stems, and larger oblong or oval leaves. 

 ?. ramosissimum. Chiefly W. in sandy soil : with nearly erect much- 

 nched and rigid striate stems 2° -4° high ; lanceolate or linear leaves taper- 

 into a petiole, and a glossy akene ; sepals 6 and stamens 6 or 3, or else 

 is 5 with 4 or 5 stamens. 



