g 4 SCHEUCHZERIACEAE. 



2. SCHEUCHZERIA L. Sp. PI. 338. 1753- 



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, racemose. 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, r-celled, each cell with i or 2 collateral ovules. Stigmas sessile, papil- 

 lose or slightly fimbriate. Carpels divergent, inflated, coriaceous, i-2-seeded, follicle-like, 

 laterally dehiscent. Seeds 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. 



Scheuchzeria. (Fig. 187.) 



Scheuchzeria palustris L. Sp. PI. 338. 1753. 



Leaves 4 / -i6 / long, the uppermost reduced to 

 bracts ; stems solitary or several, usually clothed 

 at the base with the remains of old leaves, 4 / -io / 

 tall ; sheaths of tb e basal leaves often 4' long with 

 a ligule y^' long; pedicels 3 // -io // long, spreading 

 in fruit ; flowers white, few, in a lax raceme ; per- 

 ianth-segments membranous, i-nerved, \}/ 2 ff long, 

 the inner ones the narrower; follicles 2 // -4 // long, 

 slightly if at all united at the base ; seeds oval, 

 brown, 2X // ~3 // l n g with a very hard coat. 



In bogs, Labrador to Hudson Bay and British Co- 

 lumbia, south to New Jersey, Pennsylvania, Wisconsin 

 and California. Also in Europe and Asia. Summer. 



Family 5. ALISMACEAE DC. Fl. Franc. 3: 181. 1805. 



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, pedicelled, the pedicels ver- 

 ticillate and subtended by bracts. Receptacle flat or convex. Sepals 3, per- 

 sistent. 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 be- 

 coming achenes in fruit in our species. Seeds uncinate-curved. Embryo horse- 

 shoe shaped. Endosperm none. Latex-tubes are found in all the species, 

 according to Micheli. 



About 13 genera and 65 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. 



I 't < lice Is not recurved ; calyx spreading. 2. Echinodorus. 



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



Fliiwi-rs monoecious or dioecious. 4. Sagittaria. 



i. ALISMA L. Sp. PI. 342. 1753. 



Perennial or rarely annual herbs with erect or floating leaves, the blades several-ribbed, 

 the ribs connected by transverse veinlets, or seemingly pinnately veined. Scapes short or 

 elongated. Inflorescence paniculate or umbellate-paniculate. Flowers small, numerous on 

 unequal 3-bracteolate pedicels, the petals white or rose-tinted. Stamens 6 or 9, subperigy- 

 nous. Ovaries few or many, borne in one or several whorls on a small flat receptacle, ripen- 

 ing into flattened achenes which are 2-3-ribbed on the curved back and i-2-ribbed on the sides. 

 [Greek, said to be in reference to the occurrence of the typical species in saline situations.] 



About 10 species, widely distributed in temperate and tropical regions. Only the following are 

 known to occur m North America. 



Stamens 6, strongly compressed; flowers panicled. i. A. Plantazo-aquatica. 



turgid; flowers umbelled. 2 . A. tenellum. 



