318 74. CALLITRICHACE^. 



less havings a spine on each side near tlie base and tipped with 

 the curved subulate style.— £. B. 947.— L. 2—4 times forked, 

 darh green , segments of uppermost 1. broader and more rigid. — 

 Ponds and ditches, rare. P. VI. VII. E. S. I. 



2. C. suhmer'sum (L.) ; segments of I. setaceous, fr. destitute 

 of spines covered when ripe with cyhndrical tubercles and tipped 

 with the short curved style. — K JB. 679. — X. pale green. Young 

 fr. smooth. — Ponds and ditches. P. VI. VII. E. 



Order LXXIV, CALLITEICHACE^. 



Fl. mostly monoecious, solitary, minute, usually with 2 white 

 bracts, no perianth. Stam. 1. Filamentlong. Anth. reniform, 

 1-celled, opening transversely at the top. — Perianth none. Ovary 

 1, 4-angled, 4-celled. Styles 2, subulate. Fr. dry, 4-celled, 4- 

 lobed ; separating into 4 1-seeded indehiscent carpels. Embryo 

 in axis of fleshy albumen. Radicle superior, long. Cotyledons 

 short, terete. — No stipules. — Only one genus of aquatic plants. 



1. Callit'eiche Linn. Water-Starwort. 



A. L. narrowed at the base ; lower linear, submerged ; tipper 

 floating, broad, often spathulate and forming a rosette. Fr. 

 of 4 lobes cohering in pairs. 



1. C. ver'na (L.) ; fr. nearly sessile longer than broad, lobes 

 parallel bluntly keeled on the bach convex on the sides, styles erect 

 deciduous, bracts straightish deciduous. — E. B. 722. C. vernalis 

 Kiitz. -R. V. 129. — Floating 1. ovate-spathulate, in a rosette, 

 rarely wanting. Fr. small ; keels of each pair of lobes con- 

 verging. — Ponds and slow streams. A. or P. IV. — IX. 



E. S. I. 



3. C oUnsan'gula (LeG.); fr. nearly sessile, Zoies parallel 

 with rounded edges, styles erect or spreading persistent, bracts 

 persistent. — L. all obovate, in a rosette, or lower 1. linear. Fr. 

 large, quite blunt and rounded at the edges. — Ditches. A. or P. 

 v.— IX. E. 



3. C stag'nalis (Scop.) ; fr. nearly sessile, lobes winged on the 

 back, styles erect in flower persistent and reflexed closely with 

 fruit, bracts falcate persistent .^jE. li. 8. 2864. Floating 1. 

 round-obovate-spathulate, in a close rosette, often wanting. Fr. 

 twice as large as in Sp. 1, pale when dry ; lobes parallel ( C. 

 platycarpa Kutz.) or shghtly spreading (C. stagnalis Kiitz.). — 

 Common, especially on mud. A. or P. V. — IX. E. S. I. 



