ALISMACEAE. 53 



* 



axis broadly 3-winged. In saline marshes, Md. to Fla. and La. Also in tropical 

 America. June-Sept. 



3. Triglochin maritima L. SEASIDE ARROW-GRASS. (I. F. f. 186.) Root- 

 stock without stolons, often subhgneous, the caudex thick, mostly covered with the 

 sheaths of old leaves. Scape stout, nearly terete, 0.1-0.7 m. high; leaves half- 

 cylindric, usually about 2 mm. wide; raceme elongated, often 0.4 m. long or more; 

 pedicels decurrent, 2-3 mm. long, slightly longer in fruit; perianth-segments 6, 

 each subtending a large sessile anther; pistil of 6 united carpels; fruit oblong or 

 ovoid, 5-6 mm. long, 3-4 mm. thick, obtuse at the base, with 6 recurved points at 

 the summit; carpels 3-angled, flat or slightly grooved on the back, or the dorsal 

 edges curving upward and winged, separating at maturity from the hexagonal axis. 

 In salt marshes, along the Atlantic seaboard from Lab. to N. J., and in fresh or 

 saline marshes across the continent to Alaska and Cal. Also in Europe and Asia. 

 July-Sept. 



2 . SCHEUCHZERIA L. 



Rush-like bog perennials with creeping rootstocks, and erect leafy stems, the 

 leaves elongated, half-rounded below and flat above, striate, furnished with a pore 

 at the apex and a membranous ligulate sheath at the base. Flowers small, race- 

 mose. Perianth 6-parted, regularly 2-serial, persistent. Stamens 6, inserted at 

 the base of the perianth-segments ; filaments elongated ; anthers linear, basifixed, 

 extrorse. Ovaries 3 or rarely 4-6, distinct or connate at the base, I -celled, each 

 cell with i or 2 collateral ovules. Stigmas sessile, papillose or slightly fimbriate. 

 Carpels divergent, inflated, coriaceous, i-2-seeded, follicle-like, laterally dehiscent. 

 S^eds straight or slightly curved, without endosperm. [Name in honor of Johann 

 Jacob Scheuchzer, 1672-1733, Swiss scientist.] A monotypic genus of the north 

 temperate zone. 



I. Scheuchzeria palustris L. (I. F. f. 187.) Leaves 10-40 cm. long, the 

 upper ones reduced to bracts; stems solitary or several, usually clothed at the base 

 with the remains of old leaves, 10-40 cm. tall ; sheaths of the basal leaves often 10 

 cm. long with a ligule 12 mm. long; pedicels spreading in fruit; flowers white, few, 

 in a lax raceme ; perianth-segments membranous, i-nerved, 3 mm. long, the inner 

 ones the narrower ; follicles 4-8 mm. long, slightly if at all united at the base ; 

 seeds oval, brown, with a very hard coat. In bogs, Lab. to Hudson Bay and Br. 

 Col., south to N. J., Penn., Wis. and Cal. Also in Europe and Asia. Summer. 



Family 3. ALISMACEAE DC.* 

 Water- Plantain Family. 



Aquatic or marsh herbs, mostly glabrous, with fibrous roots, scapose 

 stems and basal long-petioled sheathing leaves. Inflorescence racemose 

 or paniculate. Flowers regular, perfect, monoecious or dioecious, pedi- 

 celled, the pedicels verticillate and subtended by bracts. Receptacle flat 

 or convex. Sepals 3, persistent. Petals 3, larger, deciduous, imbricated 

 in the bud. Stamens 6 or more ; anthers 2-celled, extrorse or dehiscing 

 by lateral slits. Ovaries numerous or rarely few, i -celled, usually with a 

 single ovule in each cell. Carpels becoming achenes in fruit in our spe- 

 cies. Seeds uncinate-curved. Embryo horseshoe-shaped. Endosperm 

 none. Latex-tubes are found in all the species, according to Micheli. 

 About 13 genera and 70 species, of wide distribution in fresh water 

 swamps and streams. 



Carpels in a ring upon a small flat receptacle. i. Alisma. 

 Carpels crowded in many series upon a large convex receptacle. 

 Flowers perfect, staminate or polygamous. 



Pedicels not recurved ; calyx spreading. 2. Echinodorus. 



Pedicels recurved in fruit ; calyx appressed to the carpels. 3. Lophotocarpus. 



Flowers monoecious or dioecious. 4. Sagittaria. 



* Contributed by Mr. J. G. SMITH. 



