SPUING FLORA OF MANHATTAN. 15 



wavy. Valves veiny (4 mm. broad), one with a conspicuous thickening. 

 Low ground, common. 



B. crispus, L Resembles the foregoing but the leaves with a con- 

 spicuously wavy margin. Low ground, common. 



It. venosus, Pursh. Low (2-3 dm.) Leaves oblong, with conspicuous 

 stipules. Valves very large (2-3 cm.), orbicular, pink. Low ground, 

 infrequent. 



POLYGONUM, L. 



Calyx mostly 5 parted, all the lobes erect in fruit. Styles 2 or 3 and 

 the achene lenticular or triangnlar. 



P. aviculare, L. Low aud slender annual, prostrate or in wet places 

 upright. Leaves small. Flowers axillary. Stamens 8. Achene tri- 

 angular. Along roadsides, etc., common. 



P. Convolvulus, L Twining annual. Leaves halberd-shaped. 

 Flowers in racemes. Achene triangular. Fields, common. 



P. Pennsylvanicum,Ij. Erect annual. Leaves lanceolate. Peduncles 

 glandular. Flowers pink or white in terminal spikes. Achene 

 lenticular. Moist soil, common. 



P. Persicaria, L. Differs from the above in having the leaves often 

 marked with a dark spot, the sheaths with ciliate margin, peduncles 

 smooth and achene sometimes triangular. Wet places, common. 

 18. CHENOPODIACEAE. 



Flowers apetalous, small and green; no bracts. Stamens as many 

 as sepals, inserte 1 opposite them. Ovary 1-celled, 1-ovuled. Fruit an 

 utricle. Herbs with mostly alternate leaves and no stipules. 

 CHENOPODIUM, L. 



Sepals "). Flowers sessile in small clusters. Plants usually mealy. 

 Ours annual. 



C. album, L. Leaves ovate, more or less angulate-toothed. A 

 common weed 



C leptophyllmu, Nutt. Leaves linear, entire. Dry places, common. 



19. AMARANTACEAE. 



Flowers imbricated with dry bracts, about 3 to each flower. Ovary 

 1-celled, 1-ovuled. Herbs without stipules. 



AMARANTUS, L. 



Sepals mostly 5. Stamens 5. Fruit an utricle. Leaves alternate, 

 entire. Flowers green, very small. 



A. blitoides, Wats. Prostrate. Leaves obovate. Roadsides, etc. 

 Common in summer and autumn. 



20. NYCTACINACEAE. 



Calyx gamosepalous, colored like a corolla, the base closely sur- 

 rounding the 1-celled, 1-ovuled ovary. Corolla none. Herbs with 

 opposite-, entire leaves. 



ALLIONIA, L. 



Flowers 3-5 in an open involucre. Calyx pink. 



A. nyctaginrn, Michx. Leaves ovate, petioled. Stem M m. high. 

 Dry places, frequent. 



