16 Alismaceae 



Family 5. ALISMACEAE. Water-Plantain Family. 



A.quatic or marsh plants, with Bcapose stems and radi- 

 cal long petioled sheathing leaves. Inflorescence race- 

 mose or paniculate. Flowers regular perfect, monoecious 

 or dioecious, pedicelled ; the pedicels in whorls and sub- 

 tended by bracts. Perianth segments 6, the outer 3 

 small berbaceous persistent ; the inner 3 larger and peta- 

 loid, deciduous. Stamens 6 or more; anthers 2-celled, 

 extrorse or dehiscing by Lateral slits. Ovaries numerous 

 distincl on a Hat or convex receptacle, t-celled, L-ovuled. 

 Carpels becoming achenes in fruit. 



Flowers perfect. 1. ECHINODOBUS. 



Flowers polygamous. 2. Lophotocakpus. 



Flowers monoecious or dioecious. 3. Sagittauia. 



1. ECHINODORUS Rich. I'.ir-head. 



Perennial or annual herbs with lon^-petioled, flliptic 

 ovate or Lanceolate, often cordate or sagittate Leaves, 

 3-9-ribbed and mostly punctate with dots or lines. 

 Scapes often longer than the leaves. Inflorescence race- 

 mose or paniculate. Flowers perfect, in whorls, each 

 whorl with •'! outer bracts and numerous inner bracteoles. 

 Petals white. Receptacle large convex or globose. Sta- 

 mens 12-30. Ovaries numerous ; style obliquely apical, 

 persistent; stigmas simple. Achenes more or Less com- 

 pressed, ribbed and beaked, forming Bpinose heads. 



1. E. cordifolius (L.) ( Jriseb. Leaves variable, usually broadly 



ovate, obtuse, cordate at the base, 12-16 cm. Long and wide, so 



times lanceolate and smaller; petioles angular, striate, 6-15 cm. 

 Long; scapes 1 or more, erect 10-80 cm. high; (lowers :{-»> in each 

 whorl, on pedicels 8-12 mm. long; bracts lineardanceolate, acu- 

 minate dilated at the base; inner perianth segments shorter t lian 

 the outer, 4-6 mm. long; stamens usually L2; styles exceeding 

 the ovaries in Length; fruiting heads bur-like, 4-6 mm. in diam- 



