Hydrocharidacese — Alismaceae. 145 



II.— ANA CHARIS. 



ANA'CHARIS CANADEN'SIS. Canadian Pond-weed. 5—10. Dark green 



(1323) floating much branched, leaves linear opposite or in whorls, staminate 

 flowers unknown in this country, pistillate flowers sessile but with the 

 perianth-tube elongated so that the flowers rest on the surface of the 

 water, perianth \ in. diam. greenish purple. Ponds, ditches^ and streams, 



III. —STRA TIO TES. 

 Stratio'tes aloi'dss {15). Water-soldier. 7—8. Leaves erect sword-like 

 (1325) 6—18 in. rigid spinous-serrate deep green, flower white i^ in. diameter. 



[R. 



ORDER 81. — Alismaceae. 



Aquatic herbs with erect or floating mostly radical netted-veined leaves. 

 Perianth 6-partite. Stamens 6 — 9 hypogynous. Ovary superior. Styles 

 short or none. Stigma terminal simple or feathery. 



Leaves flat, 549 



Leaves linear, ........ Triglochin L 



Leaves triangular, ,...,,,. Butomus II. 



549 Stamens 6, ...... . Alisma IIL 



549 Stamens many, .»..,. Sagittaria IV. 



I.— TRIGLOCHIN. 



TRIG'LOCHIN PALUS'TRE (106). Arrow-Grass. 6—8. Leaves 



(1476) erect filiform, flowers inconspicuous in racemes purplish, fruit clavate 

 of 3 carpels. Marshes a?id wet fiieadows. 



TRIG'LOCHIN MARIT'IMUM (76). Leaves flattened at the top, 



(1477) flowers in dense racemes, fruit oblong of 6 carpels. Salt marshes. 



11.— BUTOMUS. 



BU'TOMUS UMBELLA'TUS (59). Flowering Rush. 6—7. Stem 

 (1475) 3 — 4 feet high, leaves triangular long and slender all radical, flowers 

 rose-red I in. diameter in an umbel with membranous bracts, perianth- 

 segments oblong spreading, stamens 9. Ditches, 



III.— ALISMA. 



Roots fibrous, leaves erect or floating, sepals 3, petals 3, stamens 6, 

 carpels 6 or more i -seeded indehiscent. 



ALIS'MA PLANTA'GO (99). Water-Plantain. 6—8. Leaves erect 



(1470) ovato-lanceolate or cordate all radical, scapes I — 3 ft, whorled, flowers 

 ^ in, diameter pink in panicles, fruit compound obtuse. Ditches. 



ALIS'MA RANUNCULOI'DES {84). Lesser Water- Plantain. 5-9. 



(1471) Leaves erect linear lanceolate all radical, scape \ — i^ ft. whorled, 

 flowers pink in umbels, fruit ribbed acute. Bogs and ditches. 



