STATE GEOLOGIST. 119 



P. orientale, L. Prince's Feather. 



LsikeFepm, Miss Manning. Infrequent. 



P. Pennsylvanicum, L. Knotweed. Polygonum. 



Frequent, or common, through the south half of the state and in the Ked river 

 valley. 



P. incarnatum, Ell. Polygonum. 



Frequent, or common, through the south half of the state. 



P. lapatliifolium , Ait., var. incanum, Koch. Polygonum, 

 Minneapolis, Roberts; lake Pepin, Miss Manning. Rare. North. 



P. Persicaria, L. Lady's Thumb. Heartweed. 



Common throughout the state, excepting near its west side, where this and the two 

 following species seem to be less frequent or rare. 



P. Hydropiper, L. Common Smartweed or Water-pepper. ' 



Common, of teu abundant, with range like the last. 



P. acre, HBK. Water Smartweed. 

 Common, with same range. 



P. hyclropiperoides , Michx. Mild Water-pepper, 



Frequent, or common, southward; also found at the lake of the Woods, Dawson, and 

 in the Red river valley, Scott. 



P. amphibium, L., var. aquaticuni, Willd. Polygonum. 

 Frequent, often common, throughout the state. 



P. Miililenbergii, Watson.* (P. amphibium, var. terrestre, in Manual. ) 

 Polygonum. 

 Common, or abundant, throughout the state. 



P. iBEartwrightii, Gray.f Polj-gonum. 



Minneapolis (common), Arthur; Blue Earth county, Leiherg; Emmet county, Iowa 

 (common), Cratty. Probably common, or frequent, throughout Minnesota. 



P. Virgiuianuni, L. Polygonum. 



Lapham, St. Croix river. Parry; Blue Earth county, LelTjerg. South. 



P. articulatuiii, L. Jointweed. 



Sandy barrens, St. Croix river, Parry; New Ulm, Juni; Minnesota Point, near 

 Duluth (plentiful), Roherts. [Upper Missouri river, Oeyer.] 



P. avicvilare, L. Knotgrass. Goose-grass. Door-weed. 

 Common throughout the state. 



*PoiiYGONUM MuHLENBERGii, Watsou. Perennial, in muddy or dry places, often 

 2 or 3 feet high, scabrous with short appressed or glandular hairs, especially upon the 

 leaves and upper stems ; leaves thin, rather broadly lanceolate, long-acuminate, usually 

 rounded or cordate at base, 4 to 7 inches long, on short stout petioles (V^ to 1 inch long) 

 from near the base of the naked sheath ; flowers and fruit nearly as in P. amphibium, 

 but spikes more elongated (i to 3 inches long), often in pairs. Proc. Amer. Acad., xiv. 



tPOLYGONtTM Hartwkightii, Gray. Strigose-hirsute or glabrous ; stem erect, 

 striate, bearing at the top thickish leaves which are broadly lanceolate, acute or 

 somewhat obtuse ; petioles short; sheaths long with a flat foliaceous limb, which is 

 setose-ciliate ; peduncle erect, eglandulose, bearing a solitary dense cylindrical spike 

 of rose-colored flowers : stamens 5 ; style deeply cleft : perigonium eglandulose. Proc. 

 Amer. Acad., viii. 



