366 
some extent. The whole trouble proves to be caused by trying 
to make two separate and distinct species one. The plant turns 
out to be P. Douglassiz, which ranges across the northern part of 
the continent from the Pacific to the Atlantic Ocean. P. Doug- 
lassii can be distinguished from its relative P. tenue at a glance, 
and is beautifully distinct, as Prof. Greene has pointed out, by its 
one-ribbed leaf in place of the three-ribbed leaf of P. enue, and 
the much longer, narrower and pediceled, drooping fruit, instead 
of the short, thick, sessile, erect fruit of that plant. 
Var. LATIFOLIUM (Engelm.) Greene, Bull. Cal. Acad. i. 125 
(1885). 
P. tenue, Michx. var. /atifolium, Fngelm., in A. Gray, Proc. 
Phila. Acad. 1863, 75. 
Colorado: Gray’s Peak (Patterson, 130); Arizona: Mokiah 
Pass (Palmer, 420); California: Tulare Co. (Palmer, 177); Ore- 
gon: Siskiyou Mountains (Howell). 
55. POLYGONUM MICROSPERMUM (Engelm). 
P. tenue, Michx. var. microspermum, Engelm, in A. Gray, 
Proc. Phila. Acad. 1863, 75. 
P. Engelmanni, Greene, Bull. Cal. Acad. i. 126 (1885). 
Colorado: Jefferson Co., Bergen Park (Greene). 
56. POLYGONUM AUSTINA&, Greene, Bull. Cal. Acad. i. 212 
(1885). 
California: Modoc Co. (Mrs. Austin); Wyoming, Yellowstone 
Park (Tweedy). 
v57. POLYGONUM SPERGULARIZFORME, Meisn. 
P. coarctatum, Dougl. ex. Meisn. in D.C. Prodr. xiv. 101 
(1856), not Meisn. 
Western North America: Straight of De Fuca (Scouler), 
California (Fremont), Borax Lake (Torrey, 426); Oregon and 
Northern California (U. S. S. Pac. Exploring Expedition, 1628). 
The specific name coarctatum was first published in Meisner’s 
Mon. Gen. Polyg., in 1826, being there applied to a Siberian plant. 
The name, therefore, cannot be used for the American species. 
Meisner left the manuscript name spergularieforme on one of his — 
labels, which is here taken up. 
58. POLYGONUM MINIMUM, 8. Watson, Bot. King, Exp. 315 
(1871). 
