2'i/pha.] MONOECIA — TRIANDRIA. 329 



invariably connate. ( W. Wilson.) Upper and floating ones generally oval 

 and stalked, 3-ribbed ; lower ones single-ribbed, linear ; rarely all linear, 



2. C. pedunculdta, De Cand. (^pedunculated Water-starwort); 

 fructiferous peduncles more or less elongated without bracteas 

 at the base, fruit regularly tetragonal, each portion bluntly keeled 

 at the back. Am. in Journ. of jSut.aiid Geogr. Sc. v. \.p. 427. — C. 

 autumnalis, Hook. i?i E. Sot. Suppl. t. 2606, (excl. the syn.^ 



Ditch at Amberley, Sussex ; Mr B oner. Fl. June. 0. 



3. C. autu?n?idlis, L. (aulnm?ial Water -startvort); fructiferous 

 peduncles very short without bracteas, fruit irregularly tetra- 

 gonal, each portion broadly and acutely winged at the back 

 Arn.—E. Fl. v. i. p. 10. HooL in E. Bat. Svppl. t. '2732 — C. 

 aquatica, y. E. Bot. t. 722, (the small Jjgure). — y. terrestris. 



Ditches, near London. Anglesea. Loch of Cluny, Scotland — y. 

 Ditton, in Mr H. C. Watson's garden. Fl. June — Oct. 0. Leaves 

 always sessile, {W. Wilson). Mr Arnott, I believe, first correctly dis- 

 tinguished the 3 British species of Callitriche, and has published them, 

 with many excellent remarks on the genus, in the work just mentioned. 



3. Zannichellia. Linn. Horned-pondweed. 



]. 7i. palustris, L. (common Horned-pondweed); E. Bot. t. 1844. 



Ditches and stagnant waters. Fl. Aug. 0. — Floating. Stems long, 

 filiform, branched. Leaves opposite, linear, entire, sometimes emargi- 

 nate at the point. Flowers axillary, from a membranaceous bractea. 

 Sterile fl. upon a very short stalk, from the base of w hich arises a single 

 naked anther, borne on a long white filament. Anthers with 2 — 4 

 cells. — The form of the stigma, the number of anther-cells, the size and 

 mode of growth, and the fruits more or less stipitate, are very variable ; 

 and several supposed species are described and figured by Reichenbach. 



4. ZosTERA. Linn. Grass-wrack. 



1. Z. marina, L. {common Grass-iorack); leaves entire, some- 

 what 3-nerved, stem roundish. E. Bot. t. 467. 



Creeks and salt-water ditches, and on the sea-shore, common. Fl. 



through the summer. If Stems various in length, as are the linear, 



obtuse, somewhat 3-nerved leaves, which have sheathing bases. Spadi.v 

 linear, arising from a sheathing portion of the leaf, which thus forms the 

 spatha. Flowers green, on one side of the spadix, quite destitute of 

 perianth, in two rows. P/s^i/s and a«Mers alternate, generally 2 anthers 

 and then 1 pistil ; both ovate, or oblongo-ovate, the germen terminated 

 by a long, filiform, bipartite style. . Anthers bursting irregularly. — This 

 plant is used in the packing of glass-bottles and earthenware. In the 

 south of Russia, Pallas tells us, it is found among pottery in old tombs. 

 Beds are frequently made of it, especially in the north of Europe : and 

 it is sold in our shops, under the name of " Alva ( Ulva or Alga) ma- 

 rina," for similar purposes. 



MONOECIA— TRIANDRIA. 



5. Typha. Linn. Cat's-tail or Reed-mace. 



1. T. latifoUa, Li. {great Reed-mace); leaves linear nearly 

 plane, sterile and fertile catkins continuous. E. Bot. t. 1453. 



