POLYGON ACEAE. Ill 



ft. Georgetown; Golden; Bergen Park; Idaho Springs; Boulder; Manitou; 

 Dale Creek ; Lower Boulder Canon. 



11. Polygonum Douglasii Greene. (P. tcnuc Coulter; not Michx.) On 

 hillsides and in sandy soil from Vt. and B. C. to N. Y., N. M. and Calif. 

 Alt. 4000-10,000 ft. Larimer Co. ; Brantly Canon, Las Animas Co. ; Pagosa 

 Springs: Wahatoya Creek; canons west of Ouray (broad-leaved form); 

 Sheepshorn Divide, Middle Park; Pagosa Peak (broad-leaved) ; Eagle River; 

 Boulder; Soldier Canon; Big Creek Gulch; Walton Creek; Arthur's Rock; 

 Bosworth ranch; Horsetooth Gulch; Chambers' Lake; Boulder; Golden; 

 Idaho Springs. 



A form more branched at the base is Polygonum Douglasii consimile 

 (Greene) Small. (P. consimile Greene) Lower Bouder Canon. 



12. Polygonum montanum (Small) Greene. (P. tcnue latifolium Engelm.) 

 In the mountains from Alb. to Colo, and Calif. Alt. 8000-12,000 ft. Mar- 

 shall Pass; Red Mountain; Ironton Park; North Park; Mt. Harvard; Silver 

 Plume ; White River Plateau. 



13. Polygonum commixtum Greene. In the mountains from Colo, to Mont. 

 Alt. 8000-12,000 ft. Silver Plume; Grizzly Creek; Cameron Pass; Mt. 

 Robinson; summit of mountains west of North Park. 



5. PERSICARIA Adans. SMART-WEED, LADY'S THUMB. 



Racemes terminal only and usually solitary ; plants aquatic. 

 Ocrea without a spreading foliaceous top. 



Plant usually floating ; leaf-blades of an oblong type, glabrous, acute or 



obtuse. i. P. coccinea. 



Plant usually diffuse and emersed ; leaf-blades of a lanceolate type, pubescent, 

 acuminate. 2. P. Muhlenbcrgii. 



Ocrea with a spreading foliaceous top ; leaf-blades narrowly oblong or lanceolate 

 (broader in floating forms), pubescent. 3. P. Hartzvrightii. 



Racemes axillary as well as terminal, numerous. 

 Ocrea without marginal bristles. 



Racemes erect ; glands on the branches and inflorescence numerous, stalked. 



4. P. omissa. 



Racemes drooping ; glands on the branches and inflorescence sessile. 

 Styles united only at the base. 5. P. incarnata. 



Styles united to about the middle. 



Leaves deep green on both sides. 6. P. lapathifolia. 



Leaves pale beneath. 7. P. incana. 



Ocrea bristle-fringed. 



Racemes oblong or cylindric, densely flowered, about i cm. thick in fruit ; 



perianth not punctate, usually pink to red-purple. 8. P. Persicaria. 



Racemes slender, loosely flowered, about 5 mm. thick in fruit ; perianth white 



or pale-green, copiously punctate. 



Racemes erect ; achenes smooth and shining. 9. P. punctata. 



Racemes nodding, at least in fruit ; achenes granular and dull. 



10. P. Hydropiper. 



1. Persicaria coccinea (Muhl.) Greene. (Polygonum amphibium Hook.; 

 not L. ; P. coccineum Muhl.) In water or rarely in mud from Me. and 

 Alaska to N. J. and Calif. Alt. up to 9000 ft West Cliff, Pike's Peak; 

 McCoy; Ouray; Veta Mountain; Hamor's Lake; Gunnison. 



2. Persicaria Muhlenbergii (S. Wats.) Small. (Polygonum Muhlenbcrgii 

 S. Wats.) In swamps, mud and shallow water from Me. and B. C. to Va. 



