42 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
12. ALISMACEAE. Water-plantain Family. 
Marsh herbs with fibrous roots, scapose stems, spongy petioles, and oval or sagittate 
leaf blades; leaves all radical; flowers perfect, monecious, or dicecious; perianth of 
3 herbaceous persistent sepals and as many white deciduous petals; stamens 6 or 
more; ovaries numerous, becoming 1-seeded achenes. 
KEY TO THE GENERA. 
Leaf blades ovate or oblong; all flowers perfect; carpels 
not winged; inflorescence paniculate............ 1. AnmsMmA (p. 42). 
Leaf blades sagittate; all or part of the flowers unisexual; 
carpels winged; inflorescence raceme-like. 
Lower flowers of the inflorescence pistillate; pedicels 
slender; leaves longer than broad............ 2. Saarrraria (p. 42). 
Lower flowers of the inflorescence perfect; pedicels 
stout; leaves broader than long.............. 3. LopHotocarrPus (p. 42). 
1. ALISMA L. WaATER-PLANTAIN. 
Perennial with long-petioled leaves, ovate or oblong, acute blades, and 1 or 2 scapes 
terminating in a loose pyramidal panicle; flowers small; carpels numerous, in a 
simple circle on a flattened receptacle. 
1. Alisma plantago-aquatica L. Sp. Pl. 342. 1753. 
Tyre Locauiry: “Habitat in Europae aquosis & ad ripas fluviorum, lacuum.” 
Ranae: Nearly throughout North America; also in Europe and Asia. 
New Mexico: Near Horace (Wooton). Wet ground. 
2. SAGITTARIA IL. Arrow HEAD. 
Stoloniferous perennial herbs with long-petioled sheathing leaves with sagittate 
blades; stems simple, bearing a few whorls of flowers, the staminate flowers above, the 
pistillate below; ovaries many, on a globular receptacle, becoming flat membranous 
winged achenes. 
1. Sagittaria arifolia Nutt.; J. G. Smith, Rep. Mo. Bot. Gard. 6: 32. 1895. 
TYPE LOCALITY: Oregon. 
Rance: British America southward through the western United States. 
New Mexico: San Juan Valley; Taos; Santa Fe; Belen; Reserve. Wet ground 
chiefly in the Upper Sonoran Zone. 
3. LOPHOTOCARPUS Durand. 
A perennial herb similar to the preceding, but the lower flowers of the inflorescence 
perfect instead of pistillate; leaves broadly sagittate. 
1. Lophotocarpus calycinus (Engelm.) J. G. Smith, Mem. Torrey Club 5: 25. 1894. 
Sagittaria calycina Engelm. in Torr. U. 8. & Mex. Bound. Bot. 212. 1859. 
Sagittaria calycina maxima Engelm. loc. cit. 
Sagittaria calycina media Engelm. loc. cit. 
TYPE Loca.ity: ‘‘On the Red River, Louisiana.” 
Rance: South Dakota and Delaware to Alabama and New Mexico. 
New Mexico: Mesilla (Wooton 74). Wet ground, in the Lower Sonoran Zone. 
Order 10. POALES. 
KEY TO THE FAMILIES. 
Leaves 2-ranked; margins of sheaths not united; stems 
mostly hollow..................0 2c eee eee cee eee 13. POACEAE (p. 43). 
Leaves 3-ranked; margins of sheaths united; stems solid. 14, CYPERACEAE (p. 110). 
