PaRT 1, 1909] ALISMACEAE 47 
or less, with numerous elongate virgate branches, the inflorescence open-paniculate, the 
floral whorls dense, numerous, separated and sometimes remote; bracts lanceolate or tri- 
angular-lanceolate, attenuate; pedicels mostly 1-4 mm. long, recurved in age; sepals 
broadly ovate or orbicular-ovate, 4.5-5.5 mm. long, obtuse, spreading or reflexed in age; 
petals white, three to four times longer than the sepals; fruit-heads globose or depressed, 
4-5 mm. in diameter, nodding; achenes about 2.5 mm. long, the body obovoid, flattish, 
prominently ribbed, the beak stout, much shorter than the body. 
TYPE LOCALITY: Panama. 
DISTRIBUTION: Panama. 
4. Echinodorus cordifolius (1,.) Griseb. Abh. K. Ges. Wiss. 
Gott. 7: 257. 1857. 
Alisma cordifolium L. Sp. Pl. 343. 1753. 
Alisma Berterii Spreng. Syst. 2: 163. 1825. 
Alisma Berteroanum Balbis; R. & S. Syst. Veg. 7: 1605. 1830. 
Alisma rostratum Nutt. Trans. Am. Phil, Soc, II. 5: 159. 1837. 
Alisma Sprengelit Kunth, Enum. 3: 154. 1. 
Lchinodorus rostratus Engelm. in A. Gray, Man. 460. 1848. 
Echinodorus rostratus lanceolatus Engelm.; A. Gray, Man. ed. 6. 556. 1890. 
Echinodorus cordifolius lanceolatus Mackenzie & Bush, Fl. Jackson Co. 10. 1902. 
Leaf-blades various, broadly ovate to lanceolate, 4-20 cm. long, obtuse or acute at the 
apex, 3-13-veined, commonly truncate or cordate at the base; petioles angled, usually 
longer than the blades; scapes solitary or clustered, 1-5 dm. tall or more, surpassing the 
leaves, simple, or branched from the lower whorls of the inflorescence; pedicels 7-15 mm. 
long, not very variable in length; bracts lanceolate or linear-lanceolate ; sepals ovate, 
4-5 mm. long, rather acute; petals white, twice as long as the sepals or less, usually 
broader; fruit-heads bur-like, globose to ovoid, 4-10 mm. long; achenes 2.5-3 mm. long, 
the body cuneate, flattish, very prominently ribbed, the beak slender, fully one half as 
long as the body. 
TYPE LOCALITY: Virginia. 
DISTRIBUTION : Illinois to Kansas, Florida, Texas, Mexico, and Central . America, Also in the 
West Indies. 
ILLUSTRATIONS: Britt. & Brown, Ill. Fl. f. 197; A. Gray, Man. ed. 7. f 4 (fruit). 
5. Echinodorus radicans (Nutt.) Engelm. in A. Gray, Man. 
460. 1848. 
Sagttlaria radicans Nutt. Trans. Am. Phil. Soc. II. 5: 159, 1837. 
Leaf-blades ovate or oblong, 5-20 cm. long, obtuse at the apex, truncate or cordate at 
the base; petioles 1-7 dm. long; scapes elongate, spreading or decumbent, creeping, 3-12 
dm. long, often solitary; whorls of the inflorescence remote; pedicels 3-12 together, 
unequal, 1.5-6 cm. long; bracts linear-lanceolate from dilated bases; sepals ovate or orbic- 
ular-ovate, 5-6.5 mm. long, rather obtust; petals white, somewhat longer than the sepals; 
fruit-heads depressed, globose or ovoid, 7-8 mm. in diameter; achenes 2 mm. long, the 
body falcate, 6-10-ribbed, the beak about one fourth as long as the body, incurved. 
TYPE LOCALITY: Fort Smith, Arkansas. 
DISTRIBUTION : Illinois to Kansas, District of Columbia, Florida, Texas, southern California, 
and Mexico. 
ILLUSTRATIONS : Britt. & Brown, Ill. Fl. f. 190; A. Gray, Man. ed. 7. f. #4 (fruit). 
6. Echinodorus virgatus (H. & A.) Micheli, in DC. Monogr. 
Phan. 3: 54. 1881. 
Alisma virgatum H. & A. Bot. Beech. Voy. 311, 1837. 
Leaf-blades ovate or oval-ovate, mostly 15-20 cm. long, rounded and sometimes mucro- 
nate at the apex, 9-ll-veined, shallowly cordate at the base; petioles elongate; scapes 
erect, at least during anthesis, often branched, the inflorescence lax, the floral whorls 
remote and loose; pedicels mostly 1-2 cm. long, recurving ; bracts ovate, acuminate, shorter 
than the pedicels; sepals ovate or oval, about 4 mm. long, reflexed in age; petals not seen ; 
fruit-heads 6-7 mm. in diameter; achenes fully 1.5 mm. long, the body obliquely cuneate- 
