CHENOPODIACEAE (GOOSEFOOT FAMILY) 



9 a Flowers in terminal or axillary spikes V? in. or more long 10 



b Flowers in axillary clusters, not in spikes 15 



10 a Spikes ovoid or oblong, densely flowered n 



b Spikes narrow, cylindric, comparatively long, loosely 



or densely flowered 12 



11 a Leaves with a triangular, dark blotch near the center; 



spikes solitary LADY'S THUMB. (P. persicaria.) 



b Leaves not with a blotch as in a; spikes numerous, in 



panicles.PENNSYLVANiAN PERSICARIA. (P. pennsylvdnicum.) 



12 a Spikes comparatively densely flowered, usually drooping 



PINK PERSICARIA. (P. incarnatum.) 

 b Spikes comparatively loosely flowered especially at base 



of spike, erect or sometimes drooping 13 



13 a Leaves with numerous translucent dots; spikes erect; 



leaves comparatively long pointed 



WATER SMARTWEED. (P. punctatum.) 

 b Leaves with few, rather inconspicuous translucent dots 14 



14 a Spikes usually drooping; sheaths fringed with short 



bristles COMMON SMARTWEED. (P. hydropiper.) 



b Spikes erect; sheaths fringed with comparatively long 



bristles MILD WATER PEPPER. (P. hydropipero\des.) 



15 a Plant prostrate; leaves lanceolate, bluish-green 



KNOTGRASS. (P. aviculare.) 

 b Plants erect 16 



16 a Stems circular; leaves oval, yellow-green 



ERECT KNOTGRASS. (P. erectum.) 

 b Stems angled; leaves linear, somewhat folded 



SLENDER KNOTGRASS. (P. tenue.) 

 5 POLYGONfiLLA COAST JOINTWEED. (P. articulata.) 



ii CHENOPODIALES. Goosefoot Order, 

 i CHENOPODIACEAE. Goosefoot Family. 



1 BfcTA GARDEN BEET. (B. vulgaris*) 



2 SPINACIA SPINACH. (S. oleracea*) 



3 BOUSSINGAULTIA MADEIRA VINE. (B. baselloUes*) 



4 K6CHIA MOCK CYPRESS. ( K. scoparia.*) 



5 CHENOP6DIUM. 



1 a Leaves with pointed teeth; plant not strongly scented.. 2 

 b Leaves with rounded teeth or lobes; plants strongly 



scented 3 



2 a Leaves rather ovate to oblong, white-mealy beneath 



PIGWEED. (C. dlbum.) 

 b Leaves triangular with few large teeth, green beneath 



MAPLE-LEAVED GOOSEFOOT. (C. hybridum.) 



147 



