Bulletin - United States National Museum - Smithsonian Institution

108 FLORA OF WASHINGTON AND VICINITY.
POLYGONACE^.
Buckwheat Family.
Polygonum orientale, L. Prince's Feather.
July.
t Polygonum Pennsylvanicum, L.
August.
Polygonum incarnatum, Ell.
July, August.
t Polygonum Persicaria, L. Lady's Thumb.
June, July.
Polygonum Hydropiper, L. Common Smartweed, Water-Pepper.
August, September.
Polygonum acre, H. B. K. Water Smartweed.
July.
t Polygonum hydropiperoides, Miebx. Mild Water-pepper.
Carberry Meadows. August.
Polygonum amphibium, L. Water Persicaria.
Pond ou the Carberry Meadows; rare. Only seen once, July 17, 1881.
Polygonum amphibium, L., var. terrestre, Willd.
Flats near the Outlet Lock. August.
t Polygonum Virginianum, L.
August.
t Polygonum aviculare, L. Knotgrass. Doorweed.
June, July.
t Polygonum erectum, L. [P. aviculare, L., var. erecium, Roth.]
July.
t Polygonum arifolium, L. Halberd- leaved Tear-Thumb.
September.
+ Polygonum sagittatum, L. Arrow-leaved Tear-Thumb.
August, September.
t Polygonum Convolvulus, L. Black Bindweed.
July to November.
Polygonum dumetorum, L. Climbing False Buckwheat.
August, September.
t Polygonum dumetorum, L., var. scandens, Gray.
Fagopyrum esculentum, Moench. Buckwheat.
Occasionally found in the vicinity of fields. August.
Rumex Britannica, L. Pale Dock.
May