358 



POLYGONACEAE (BUCKWHEAT FAMILY) 



filaments broad at base; styles 3; cotyledons incumbent; albumen horny, 

 glabrous annuals, except nos. 1 and 2. 



Achenes conspicuously exserted. 



Prostrate, maritime ; achene broadly ovoid-pyramidal. 



Calyx-lobes petaloid, broadly obovate ; foliage nearly white . . . 1. P. maritimum. 

 Calyx-lobes subherbaceous, oblong ; foliage pale green . . . . 2. P. fowleri. 



Erect ; achene elongated, lanceolate-pyramidal 3. P. exsertum. 



Achenes nearly or quite included by the fruiting calyx. 

 Branches terete or nearly so. 

 Flowers small; sepals (normally 5) white or roseate, 1.3-1.8 mm. long; 



pedicels included. 

 Erect, much branched ; leaves linear-oblong, slightly rigid ; flowers 



much surpassed by the bristle-like remnants of the stipules . 4. P. prolificum. 

 Prostrate or rarely erect ; leaves not firm, bluish green ; flowers 



mostly exserted beyond the hyaline flaccid torn stipules . . 5. P. aviculare. 

 Flowers larger, the pedicels exserted ; sepals (often 6) 2-3 mm. long. 



Leaves elliptical, yellowish green, obtuse 6. P. erectum. 



Leaves lanceolate, acute 7. P. ramosissimum 



Branches rather sharply angled. 



Leaves strongly plicate ; flowers erect 8. P. tenue. 



Leaves flat with re volute margins ; flowers nodding . . . . 9. P. Douglasii. 



1. P. maritimum L. Prostrate, very 

 glaucous, nearly white; leaves mostly 

 small, linear-oblong, very thick, usually 

 exceeding the short internodes ; stipules 

 silvery ; sepals broadly obovate, petaloid, 

 contracted at the base, the broad ro- 

 seate tips inclining to spread in fruit. 

 Sandy sea-coast, Mass, to Fla., local. 

 (Eu.) FIG. 706. 



2. P. FowlSri Robinson. Prostrate, 

 pale green ; leaves narrowly elliptic, 

 about equaling the full grown inter- 

 nodes; sepals oblong, herbaceous with 

 white or roseate margin, not con- 

 tracted at the base, rather closely ap- 

 pressed to the achene. (P. Eayi Am. 

 auth., not Babington.) Sea-coast, e. 



Canada and Me.; also Wash, to Alaska. FIG. 707. 



3. P. exs6rtum Small. Erect much branched annual, 3-8 

 <lm. high ; leaves lanceolate, rather light or pale green, 1-3 

 cm. long, usually exceeded by the internodes ; sepals oblong, 

 green, normally 5, unequal, closely appressed to the base 

 of the much exserted chestnut-colored ovate-lanceolate achene. 



Brackish meadows, N. B. to N. J. ; 



and on sand-bars and prairies, 111. , Mo. , 



and Neb. to the Saskatchewan. FIG. 



708. 



4. P. prolificum (Small) Robinson. 

 Erect or nearly so, much branched, 

 slightly rigid, 3 dm. high ; leaves linear- 

 oblong, obtuse or acute, firm, in a dried 

 state veiny ; stipules soon frayed to 



bristle-like remnants surpassing considerably the small 

 sessile roseate 5-parted flowers. (P. ramosissimum, var. 

 Small.) Sea-shore, e. Que. to Va, ; also Mo., Neb., and 

 Kan. FIG. 709. 



5. P. aviculare L. Slender, mostly prostrate or ascend- 

 ing, bluish-green ; leaves lanceolate, 0-20 mm. long, usually 

 acute or acutish ; sepals hardly 2 mm. long, green with 

 pinkish margins ; stamens 8 (rarely 5) ; achene dull and 

 minutely granular-striate, mostly included. Common every- 

 where in yards, waste places, etc. (Eurasia.) FIG. 710 a. 



706. P. maritimum. 

 Flowering branch x %. 

 Fruiting calyx X 3. 

 Stem-leaf x 1. 



707. P. Fowleri. 

 Upper part of stem 

 x%. 



Fruiting calyx X 3. 



708. P. exsertum. 

 Fruiting calyx x S. 

 Stem leaf x %. 



709. P. prolificum. 

 Flowering branches 



xy a . 



