1902] Robinson, — Polygonums of Section Avicularia 73 



P. DouoLASll, Greene. Leaves revolute at the margins, otherwise 

 nearly flat, obscurely or not at all plicate : flowers soon deflexed. — 

 Bull. Calif. Acad. Sci. i. 125 (1884); Small, Monog. Gen. Polyg. 118, 

 t. 46— Vermont, Snake Mountain, in thin soil on sand rock, 14 

 Sept. 1878, and 22 Aug. 1900, E. Brainerd; Castleton, 22 Aug. and 

 12 Sept. 1897, A. J. Grout 6- IV. IV Eggleston. Also westward 

 along the Great Lakes to Rocky Mountains and Pacific Slope. 

 Plate 35, fig. 21. 



P. tenue, Michx. Leaves strongly plicate lengthwise, furrowed 

 on each side of the midnerve : flowers erect or nearly so. — Fl. i. 

 238 (1803); Meisn. in DC. Prodr. xiv. 100; Small, Monog. Gen. 

 Polyg. 122, t. 48.— Dry sandy soil, mostly in open places. Massa- 

 chusetts: Melrose, 28 Sept. 1878, H. A. Young; Maiden, 25 Oct. 

 1886, F. S. Collins; Medford, 14 Oct. 1853, W. Boott; Arlington, 

 15 Aug. 1869, W. Boott \ Cambridge, 4 Sept. 1891, M. L. Femald; 

 Weston, Summit of Doublet Hill, 14 Oct. 1894, E. F. Williams; 

 Milton, on Blue Hill, 14 Aug. 1884, C. F. Faxon, 11 Aug. 1895, 

 F. F. Williams. Rhode Island, Providence, 10 Aug. 1877, /. IV. 

 Congdon; near Apponaug, 18 Aug. 1886,/. A Collins. Connecti- 

 cut : New Haven, D. C. Eaton ; Stratford, on dry exposed sands, 

 29 Aug. 1892, and 14 Sept. 1895, E. H. Fames; Fairfield, 14 Aug. 

 1891, F. H. Fames; Southington, in dry fields, 28 Sept. 1898, 

 L. Andrews, no. 256, and C. H. Bissell. Also frequent and locally 

 abundant southward and west to Minnesota. Plate 35, fig. 20. 

 Gray Herbarium, Cambridge, Massachusetts. 



Explanation of Plate ^.—Polygonum ramosissimum; fig. i, fruiting 

 calyx ; fig. 2, a part of the inflorescence; fig. 3, a stein leaf. P. prolijicum : 

 fig. 4, upper part of a branch. P. aviculare : fig. 5, end of a branch. P. 

 aviculare, vav. vegetutu: fig. 6, leaf. P. aviculare, var. attgustissimum ; fig. 

 7, leaf. P. aviculare, var. littorale : fig. S, a part of the stem and branches. 

 P.erectum: fig 9, end of a branch. P. Bellardi: fig. 10, inflorescence; fig. 

 11, a stem leaf. P. exsertum: fig. 12, fruiting calyx and mature achene ; fig. 

 13, a stem leaf. P. Fowleri: fig. 14, a part of the stem ; fig. 15, fruiting 

 calyx and achene. P. Roberti : fig. 16, fruiting calyx and achene (drawn 

 from English material). P. maritimum: fig. 17, branch; fig. 18, fruiting 

 calyx and achene; fig. 19, a stem leaf. P. tenue: fig. 20, a stem leaf (cut 

 transversely to show plicate character). P. Douglasii : fig. 21, a stem leaf. 



Figs, i, 12, 15, 16, and 18, are magnified to 5 diameters; the others are 

 natural size. 



