Marsh herbs, with parallel-veined, petiolate leaves and brandling peduncles. Flowers perfect or monoecious, with a regular double perianth. Sepals 3, green; petals 3, colored or green; stamens hypogynous. Ovaries 3 or more, separating into as many 1 -seeded achenia.

Genera 9, aperies 70, distributed in all parts of the world, more common in temperate climates. One species of Sagittaria is cultivated for food in China (S. Sinensis). (Our specimens were revised by Dr. Engelman.)

Suborders And Genera

I. ALISMEae. Petals white, with a green calyx.

Embryo curved. Leaves rush like, with no lamina, (a) a Fls

Embryo curved. Leaves rush-like, with no lamina, (a) a Fls. all perfect.

Stam 6. Alisma. 1.

Stam. 9. - 24. ECHIN. 2.

a Fls. diclinous. Stam. ∞.. .SAGTIARIA. 3 II. JUNCAGINEae. Petals greenish, like the sepals.

Embryo straight. Leaves mostly expanded to a lamina, (b) b Anthers oval. Lvs. radical... TRIGLOCHIN. 4 b Anth. linear. Lvs. cauline.SCHEUCHZERIA. 5

FIG. 712. Inflorescence of a Sagittaria, leaf and flowers. a, One of the pistils enlarged, b. The pistil of A lisma cut open, showing the seed and curved embryo.

1. ALIS'MA, L. Water Plantain. (Celtic alls, water?) FlowersSuborders And Genera 1927 ; sepals 3, persistent; petals 3, aestivation involute; stamens 6; ovaries and styles numerous, arranged in a circle, forming as many flattened achenia. - Suborders And Genera 1928 Acaulescent, marsh herbs, with mostly expanded leaves, and with panicled flowers.

A. plantago L. Lvs. all radical, ovate or oval, subcordate, abruptly acuminate; scape many-flowered; lis. verticillate in the panicle; carpels 15 to 20, ribbed on the back, forming an obtusely triangular wholl. - A common, smooth, handsome inhabitant of pools and ditches. Lvs. resembling those of the common plantain, with about 5 veins running from end to end, connected by cross veinlets. Petioles 8 - 12' long. Panicle a scape, 1 - 2f high, with numerous, small, rose-white flowers. Jl., Aug. (A. trivialis and parviflora Ph.)

2. ECHINODO'RUS, Richard, Engelm. (Gr.Suborders And Genera 1929 the sea-urchin,

Suborders And Genera 1930 a sack; alluding to the head of carpels bristly with the persistent styles.) - Flowers Suborders And Genera 1931 ; sepals 3, persistent; petals 3, aestivation imbricate; stam. 6 - ∞; ovaries and styles ∞, imbricated in a head, forming as many flattened, beaked achenia. - Scape creeping or erect, flowers verticillate.

1 E. radicans Engelm. Leaves ample, ovate, obtuse, cordate, about 7-veined, on long petioles; scape prostrate, running and rooting at the proliferous joints; fls.

clustered at the nodes, on long pedicels; stam. 18 - 24; heads of carpels ovoid, achenia short-beaked, very numerous (100 - 209). -Suborders And Genera 1932 Swamps, W. I11. (Engel-mann in Gray's Manual) S. to Ga. (Mettauer) and La. (Hale). Lvs. 5 - 12' by 3 - 7', strongly heart-shaped. Scapes' several, 2 - 4f long, producing roots and small leaves as well as flowers at the upper joints. Flowers white, much resembling those of Sagittaria. Jn., Jl. (Alisma, Nutt.)

2 E. rostratus Eugelm. Leaves ovate, rather acute, cordate, about 5-veined, the later ones oblong, all long-petioled; scapes erect, much exceeding the leaves, sharply angled; stam. 12; heads of carpels globular; ach. numerous (100), strongly ribbed and beaked. -Suborders And Genera 1933 River swamps, Ill near St. Louis (Engelm.) S. to Ark. Much smaller than the preceding. Lvs. 1 - 3' long, petioles 2 - 4'. Scapes 1 - 3f. Flowers about half as large as in Sagittaria. (Alisma, Nutt.)

3 E. parvula Engelm. Dwarf; leaves elliptic-lanceolate, very acute, tapering to a petiole of equal length; scapes erect, 3 - 6-flowered; pedicels reflexed in fruit; stam. 9; heads of carpels depressed-globular; ach. about 20, beakless. -Suborders And Genera 1934 Muddy shores, Ill., Mo. to Mich. (Engelm.). Plant a few inches (1 - 3 or 4') high, often stoloniferous. Leaves, excluding petiole, less than 1' long. Fls. about 3" diameter.

3. SAGITTARIA, L. Arrow-head. (Lat. sagitta, an arrow; from the peculiar form of the leaf.) - Flowers 8 , rarelySuborders And Genera 1935Suborders And Genera 1936 , sepals 3; petals larger, colored, aestivation imbricate;. stam.∞ ; ovaries very numerous, crowded into a head, forming in fruit as many flat, margined, beaked achenia. - Acaulescent marsh herbs, with a milky juice. Lvs. commonly arrow-shaped, often lanceolate, linear, or even reduced to mere petioles. Scapes with fls. in whorls of 3s, the lower perfect. Petals white.

§ Lower (fertile) pedicels much shorter than the upper (sterile) ones......

Nos. 1, 2

§ Fertile pedicels as long as the sterile, (a)

a Filaments longer than the anthers. Lvs. not sagittate.......................

No. 3

a Filaments very short. - Leaves lanceolate and linear, mostly.............

Nos. 4 - 6

- Leaves oval - obtuse, sagittate at base..........

No. 7

1 S. variabilis Engelm. Lvs. generally sagittate; scape 12-angled, upper fls. sterile, on pedicels but twice longer than those of the lower fertile fls.; fil. glabrous, longer than the anthers; ach. obovate, with a conspicuous, averted beak. - A curious aquatic, conspicuous among the Rushes and Sedges of sluggish waters, Can. and U. S. Lvs. 3 to 10', the lobes about as long as the lamina, petioles much longer. Scape 10' to 2f, simple or branched, 3 of the angles prominent. Fls. mostly in 3s, with ovate, slender-pointed bracts, often dioecious. Petals roundish, showy, wholly white. Jl, Aug. The leaves arc exceedingly variable. (S. sagittifolia, Ed. 1; etc, nee. L., from which it differs, according to Dr. Engelmann, in the characters emphasized above.)

β. obtusa. Lvs. large, broadly ovate, sagittate, apex obtuse; fls. dioecious. -

A large form, Mid., W. and S. States. (S. obtusa Willd.) γ. latifolia. Lvs. large, broad-ovate, acute, with ovate, acnminate lobes. §. gracilis. Lvs. linear, with linear, long, acute, spreading lobes. є. pubescens. Plant pubescent in all its parts; lvs. and their lobes ovate.