POLYGONACEAE (BUCKWHEAT FAMILY) 



359 



710, P. aviculare. 

 a. Typical form x %. 

 6. V. littorale x %. 



c. Stem-leaf of V. vegetum x %. 



d. Stem-leaf of V. angust. X24. 



doubtless elsewhere. 

 6. P. erectum L. 



Var. littorHle (Link) Koch. Leaves 

 thick, often obtuse ; achenes slii^htiy 

 shining, obscurely i)unctate or jiunctate- 

 striate. (P. littorale Link.) — A mari- 

 time and littoral form sometimes char- 

 acteristic, but passing to the tyj ileal 

 form and separated by no constant 

 character. (Eu.) Fig. 710 6. 



Var. vegetum Ledeb. LarL^er, erect 

 or nearly so ; the leaves (often ."> cm. 

 long) oblong or narrowly elli}.tic, thin, 

 the margins crisped. — Rich soil and in 

 shade. (Eu.) Fig. 710 c. 

 Var. angustissi- 

 « mum Meisn. 

 Leaves linear, 5-9 

 times as long as 

 broad. — Summit 

 of Mt, Monad- 

 nock, N. H., and 

 (Eu.) Fig. 710 d. 



Stout, erect or ascending, yellowish- 

 green ; leaves elliptical^ 1.3-6 cm. 

 long, usually obtuse ; flowers yel- 

 lowish-green, about 3 mm. long, 

 on more or less exserted pedicels; 

 stamens 5-^ ; achene dull, included. 

 — Waysides, waste places, etc. Fig. 

 711. 



7. P. ramosissimum Michx. 

 Erect or ascending, O.G-1.9 m. high, 

 yellowish-green; leaves lanceolate (2-5 cm. long), 

 acute; sepals 6, the 3 outer 2-3 mm. long, carinate, 

 cucullate at the summit, drying green with yellow mar- 

 gins ; the inner sepals smaller, yellow; stamens 3-6; 

 achene smooth, shining, included. (P. camporum of 

 Bit of flowering branch x %. ^^^^i. in part, not Meisn.) —Sandy soil, Me. and Mass., 

 Stem-leaf X 2/3. j^^^^ . ^^ p^^ . jj^^ ^^ Minn., Tex., and westw. Fig. 



712. Forma atlAnticum Robinson. Sepals 5 or rarely 6, roseate, not dning 

 yellow, nor even yellowish. — Frequent on the coast, Me. to R.I. In habit 

 identical with the typical western form. 



8. P. tenue Michx. Stem angled, erect (1.5-4 dm. high), 

 glabrous, or slightly scabrous at the nodes ; leaves narrowly lan- 

 ceolate to linear, 2-5 cm. long, acute at each end, 

 A strongly plicate; flowers usually solitary, nearly 



sessile, erect; stamens 8; achene included, dull 

 black.— Dry soil, s. Me. to S. C, w. to Man., Minn., 

 Neb., and Tex. Fig. 713. 



9. P. Douglasii Greene. Stem angled, erect; . . ^^ 

 leaves lanceolate to linear, acute at each end, slightly -* '3- 



^ rigid, the margins revolute but the surface not plicate ; pedicel! 



714. P. Doug- short but slender; flowers soon deflexed. — Rocky or sterile soil 

 ^^^^^' w. Me. to n. N. Y., Ont., and westw., local; common in Rockj 



Stem-leaf X 2/3. ^^^^ Fig. 714. 



§2. BISTORTA [Tourn.] L. Glabrous alpine perennials, with tldclchulh-Ukt 

 caudex and simple stems; flowers in a spike-like raceme; calyx colored, 

 deeply 5-cleft ; stamens 8 ; styles 3, long. 

 10. P. viviparum L. Smooth, dwarf (4-35 cm. high), bearing a linear erect 



spike of flesh-colored flowers (or often little red bulblets in their place) ; leave > 



711. P erectum. 

 Flowering branch x %. 



712. P. ramosissimum 

 Fruiting calyx x 3. 



713. P. tcnur. 

 Stem-leaf (cii*. 

 to sht)\v plicat ) 



