le Pe natans Le ————— > Stems mostly simple, the blades of the 
floating leaves oval or ovate, leathery , {5-8 cm. long, 3-5 cm. broad, 
id 
rounded or obtuse at the apex, rounded a ve cordate 
at the base, borne on stout petioles 5-20 cm. long; submerged leaves 
reduced to b Ss tiogles want ; Stipules rather firm, 4-6 cm. 
aa aptoaaie Spikes cylindrical, 2-5-5 cm. long, 1 cm. broad in fruit, 
borfe on stout peduncles 5—15 cm. long; nutlets 4 mm. long. 
Common in shallow pools, in marshes and along lake shores. 
£- Pe amplifolius @uckerme -———_—+Stems elongate, mostly simple, the 
blades of the floating leaves oval, 6-8 cm. long, obtuse or rounded at both 
ends, 50-40 veined, borne on petioles 5-10 cm. long or longer; submerged 
leaves strongly undulate, mostly petioled, the uppermost elliptical or ovate, 
GS-12 cme long, 3-6 cme wide, the lower narrower and elongated; stipules 
4-12 cm. long, acute or acuminate; spikes cylindricalas2e5-5 cm. long, borne 
on stout peduncles 5-20 cm. long; nutlets 1.5-4 mm. long, smooth, 5-keeled , 
the middle keel prominent. 
Frequent in shallow water of lake margins. 
ee 
Oe Pe americanus C. & Se ———-—> Stems much-branched, the vlades of 
the floating leaves elliptical, 5-8 cm. long, 1-2.5 cm. wide, messy obtuse 
at both ends\and abruptly narrowed to petioles 1-3 cm. long, submerged leaves 
iinear-lanceolate or linear-oblanceolate, 10-15 cm. long, subequal to the 
floating leaves in width or narrower, narrowed to distinct petioles 3-5 cm. 
long or longer; spikes cylindrical, 2-4 cm. long, 6-7 ma thick at maturity, 
borne on peduncles about as thick as the stems, 2-4 cm. long; nutlets 
smooth, d-keeled, the middle keel prominent. 
Ste Marie's slough, Epling and Offord 8031. 
or pointdd at 
eens oe 
