FLORA OF WORCESTER COUNTY. 307 
Acorus, L. Sweet Flag. 
Calamus, L. Moist grounds, not rare. 
LEMNACE., 
Lemna, L. Duckweed. 
minor, L. Stagnant waters, common. 
ALISMACEi, 
‘Ausma, L.  Water-Plantain. 
Plantago, L. Shallow water, common. 
Sacittari, L. Arrow-head. 
variabilis, Engelm. In water or wet places. Common. 
ae i var. *obtusa. G. £. Stone. 
xs “  *angustifolia. eA 
i “ *diversifolia. Princeton. 
WLW. B.& J. F.C. 
i a “ gracilis, Engelm. G. &. Stone. 
graminea, Michx. Seed oe 
NATADACE. 
PoTaMocEron, Tourn. Pondweed. (By the late Rev. Thos. 
Morong.) 
natans, L. Very common. 
« © var. *prolixus, Koch. ms as 
Oakesianus, Robbins. Uxbridge. 
Pennsylvanicus, Cham. Common in streams and ponds. 
Vaseyi, Robbins. Lake Quinsigamond. 
Spirillus, Tuckerm. Common. 
hybridus, Michx. ik 
fluitans, Roth. Worcester. Aiss £. W. Sargent. 
