454 
+ + Fronds oblong to elliptical, sessile, soon separating. 
9, L. Valdiviana Philippi. Fronds elliptic-oblong, small (2 mm. long), rather thick, 
obscurely one-nerved: spathe broad-reniform: utricle long-ovate, pointed by the 
long style: seed oblong, with prominent acute operculum, (ZL. Torreyi Austin).— 
Pools and slow-running waters. 
3. L. minor L. Fronds round- to elliptical-obovate (2to3 mm, in diameter), rather 
thick, obscurely 3-nerved: spathe sac-like: utricle short-urn-shaped, tipped with a 
short style: seed oblong-obovate, with prominent rounded operculum,—Every where 
in stagnant waters. 
** Ovules 2 to 7: fronds obscurely 5-nerved. 
4. L.gibba L. Fronds obovate-elliptic to nearly orbicular (3 to 6 min. long), very 
thick and spongy, flat above, almost hemispherical, soon separating: bract sac-like.— 
Extending from Missouri through Texas to Arizona and California. 
3. WOLFFIA Horkel. 
Simplest and smallest of flowering plants, with rootless fronds pro- 
liferous from a cleft or funnel-shaped opening at base, 2 flowers (one a 
single stamen, the other a globular ovary) bursting through the upper 
surface of the globular and loosely cellular frond, 1-celled 2-valved 
anther, short style, depressed stigma, and a spherical utricle. 
1, W. Columbiana Karsten. Globose or globular, 0.6 to 1.3 mm, in diameter, light 
green all over, not dotted: stomata 1 to 6: opening at base circular and with athin 
border.—Floating rather beneath the surface of stagnant waters, extending from the 
north Atlantic States to Louisiana and through Texas to Central Mexico. 
ALISMACEH. (WATER-PLANTAIN FAMILY.) 
Marsh herbs, with fibrous roots, scape-like stems, transversely-veined 
sheathing petioled radical leaves, perfect or moncecious or diccious 
flowers, perianth of 3 herbaceous persistent sepals and as many white 
deciduous petals, 6 or more included stamens, and numerous 1-celled 
ovaries becoming 1-seeded achenes in fruit. 
1. Alisma. Flowers perfect: carpels flattened, in one whorl. 
2. Sagittaria. Flowers mostly unisexual: carpels flattened, in dense heads 
winged, 
3, Echinodorus. Flowers perfect: carpels capitate, turgid and ribbed, 
1. ALISMA L. (WATER-PLANTAIN.) 
Herbs in shallow water or mud, with severalribbed leaves, small 
white perfect flowers in a verticillately branched panicle, mostly 6 
stamens, somewhat channeled (on back) obtuse achenes in a crowded 
whorl. 
1. A.Plantago L. Perennial by a stout proliferous corm: leaves long-petioled, 
ovate, oblong, lanceolate, or even linear, acute, mostly rounded or cordate at base, 
3 to 9-nerved: panicle (3 to 6 dm. long) loose, compound, many-flowered: carpels 
obliquely obovate, forming an obtusely-triangular whorl in fruit.—Shallow water 
and ditches, everywhere. 
