70 NORTH AMERICAN FLORA (VoLumME 17 
mm. long, 24 mm. wide, minutely serrulate ; staminate flowers unknown; flowers in the 
typical American form usually hermaphrodite, in the European (Axacharis Alsinastrum), 
pistillate; sheath tubular, 1-1.5 cm. long ;. tube of the hypanthium 5-10 mm. long; sepals 
and petals elliptic, obtuse, about 1.5 mm. long; stamens usually 3, rarely 4-6, or reduced 
to mere filaments; anthers oblong, nearly sessile ; stigmas 3, spreading, purplish, emargi- 
nate, about equaling the petals and sepals. 
TYPE LOCALITY: Rivers of Canada. 
DISTRIBUTION : Slow streams and ponds, from Quebec to Virginia and Minnesota; also in 
Europe, but only introduced as the pistillate 4. Alsinastrum. 
ILLUSTRATIONS: (all of A. Alsinastrum:) Ann. Sci. Nat. III. 11: p/. 1; Bot. Zeit.16: pl. 9; 
Jahrb. Wiss. Bot. 1: p/. 27, f. 40-47, pl. 28. 
2. Philotria Nuttallii (Planch.) Rydb. Bull. Torrey 
Club 35: 461. 1908. 
Serpicula verticillata Muhl. Cat. 84. 1813. Not.S. verticillata I,. 1781. 
Udora canadensis Nutt. Gen. 2: 242, 1818 
UVdora verticillata Spreng. Syst. 1: 170, in part. 1825. 
Anacharis Nuttallii Planch. Ann. Mag. Nat. Hist. II. 1: 86. 1848. 
Dioecious water-plant; stem slender, 3-10 dm. long, 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, 5-10 mm. long, 2-3 mm. wide, finely serrulate; spathe of the staminate flowers 
ovoid, sessile, 5-6 mm. long; flower without a tube; sepals and petals oblong, the former 
scarcely exceeding the oblong anthers, which are 2-2.5 mm. long; sheath of the pistil- 
late flowers about 1 cm. long, 2-cleft; tube of the hypanthium 5-15 cm. long; sepals 
and petals elliptic, 1.5 mm. long; filaments rudimentary; stigmas slightly exceeding the 
petals, 2-cleft at the apex. 
TYPE LOCALITY : North America. 
DISTRIBUTION : Slow streams and ponds, from New York to Virginia. 
ILLUSTRATIONS: Torr. Fl. N. Y. pl. 125; Britt. & Brown, Ill. Fl, S 207; E. & P. Nat. PAl. 
21: fig. 184, Cand D (all as Zlodea or Philotria canadensis). 
3. Philotria angustifolia (Muhl.) Britton; Rydb. Fl. Colo. 15. 1906. 
Serpicula verticillata angustifolia Muhl. Cat. 84. 1813. 
? Serpicula occidentalis Pursh, Fl. Am. Sept. 1: 33. 1814. 
Serpicula canadensis Eat. Man. ed. 5. 390. 1829. 
? Apalanthe Schweiniizii Planch. Ann, Mag. Nat. Hist. II. 1: 87. 1848. 
? Flodea Schweinitzii Casp. Jahrb. Wiss. Bot. 1: 468. 1858. 
Dioecious water-plant; stem slender, flaccid, 3-10 dm. long; leaves in 3’s or 2’s, sessile, 
linear, 1-2 cm. long, about 1 mm. wide, rarely 1.5 mm. wide, acute; spathe of the stami- 
nate flowers 2-3 mm. long, sessile, ovoid; sepals and petals elliptic or oval, the former 
about 2 mm. long, the latter smaller; anthers about 1 mm. long; spathe of the pistillate 
flowers tubular, 1-2 cm. long; hypanthium-tube 3-10 cm. long; sepals and petals elliptic, 
the former 1.5-2 mm. long; stigma 2-cleft. 
TYPE LOCALITY: Pennsylvania. 
DISTRIBUTION: Slow streams, from New York and Pennsylvania to Florida. 
4. Philotria minor (Engelm.) Small, Fl. SE. U. S. 47. 1903. 
Udora verticillata (?) minor Engelm.; Casp. Jahrb. Wiss. Bot. 1: 465, as synonym under Azacharis 
Nuttaliiz. 1858. 
Dioecious water-plant; stems filiform, 3-5 dm. long; leaves in 3’s or 2’s, linear, 
5-8 mm. long, 1 mm. broad or less, acutish.; staminate spathe about 5 mm. long, ovoid, 
sessile; sepals and petals oval, 1-1.5 mm. long; anthers about 1 mm. long; pistillate 
spathe about 1 em. long; hypanthium-tube 2-5 cm. long (rarely longer); petals and sepals 
elliptic, 1-1.5 mm. long; stigmas slender, longer than the sepals, deeply 2-cleft. 
TYPE LOCALITY: St. Louis, Missouri. 
DISTRIBUTION : Ponds, lakes, and slow streams, from Ohio and Kentucky to Wisconsin, Kan- 
sas, and Arkansas. 
ILLUSTRATION: Jahrb. Wiss. Bot. 1: pl. 29, f. 70-74. 
