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.

3 Philotria Nuttallii Planch Rydb Nuttall s Water  2503 Philotria Nuttallii Planch Rydb Nuttall s Water  251

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.