2. Philotria Angustifolia (Muhl.) Britton. Narrow-Leaved Water-Weed

Fig. 249

Serpicula verticillata angustifolia Muhl. Cat. PI. Am.

Sept. 84. 1813. ?Serpicula occidentalis Pursh, Fl. Am. Sept. 33. 1814. lApalanthe Schweinitzii Planch. Ann. Sci. Nat. Bot. III.

11: 76. 1849. Philotria angustifolia Britton; Rydb. Bull. Agr. Exp.

Sta. Colo. 100:. 15. 1906.

Dioecious water plant; stem slender, flaccid, 1°-3 1/2° long. Leaves in 3's or 2's, sessile, linear, 5"-10" long, about 1/2" wide, rarely 3/4" wide, acute; spathe of the staminate flowers 1"-1 1/2" long, sessile, ovoid; sepals and petals elliptic or oval, the former about 1" long, the latter smaller; anthers about \" long; spathe of the pistillate flowers tubular, 1/2"-1" long; hypanthium 1 1/4'-4' long; sepals and petals elliptic, the former \"-\" long; stigmas 2-cleft.

In streams New York and Pennsylvania to Florida.

3. Philotria Nuttallii (Planch.) Rydb. Nuttall's Water-Weed

Fig. 250

Serpicula verticillata Muhl. Cat. PI. Am. Sept. 84. 1813.

Not S. verticillata L. 1781. Anacharis Nuttallii Planch. Ann. & Mag. Nat. Hist. II. 1:

85. 1848. Philotria Nuttallii Rydb. Bull. Torrey Club 35: 461. 1908.

Dioecious water-plant; stem slender, 1°-3 1/20 long; with the internodes often longer than the leaves. Leaves usually in 3's or the lower ones in 2's, sessile, oblong or lance-oblong, acute, 2 1/2"-5" long, 1"-1 1/2" wide, finely serrulate; spathe of the staminate flowers ovoid, sessile, 2 1/2"-3" long; flower without a tube; sepals and petals oblong, the former scarcely exceeding the oblong anthers, which are i"-i 1/2" long; sheath of the pistillate flowers about 5" long, 2-cleft; tube of the hypanthium 2'-6' long; sepals and petals elliptic, 3/4" long; filaments rudimentary; stigmas slightly exceeding the petals, 2-cleft at the apex.

In slow streams and ponds, New York to Virginia. This figure was used for P. canadensis in our first edition, formerly confused with this species.

4. Philotria Minor (Engelm.) Small. Lesser Water-Weed

Fig. 251

Udora verticillata (?) minor Engelm.; Casp.

Jahrb. Wiss. Bot. 1: 465, as synonym under Anacharis Nuttallii. 1858.

Philotria minor Small, Fl. SE. U. S. 47. 1903.

Dioecious water-plant; stems filiform, i°-i|° long. Leaves in 3's or 2's, linear, 2 1/2"-4" long, i" broad or less, acutish; staminate spathe about 2\" long, ovoid, sessile; sepals and petals oval, 1/2"-3/4" long; anthers about i" long; pistillate spathe about 5" long; hypan-thium-tube3/4'-2' long (rarely longer); petals and sepals elliptic, i"-¥' long; stigmas slender, longer than the sepals, deeply 2-cleft.

In ponds, lakes and slow streams. Wisconsin to Ohio, Kentucky, Kansas and Arkansas.