80 The Flora of Wiltshire. 



zig-zag, very much branched, variable in length according to the 

 stillness or rapidity of the stream. Leaves alternate, slender, 

 tapering, acute. Spikes few, solitary, on long peduncles from the 

 uppermost forks of the branches, rising just above the surface. 

 Flowers 2 or 3 together, dull green. Nut with strong lateral ridges. 



8. P. densus, (Linn.) close-leaved Pondweed. Engl. Bot. t. 397. 

 Reich Icones, vii., 28. 



Locality. In the Kennet and Avon Canal, and ditches. P. Fl. 

 June, July. Area, 1, * 3, 4, 5. Not unfrec[uent in JFilts. Leaves 

 crowded, all opposite, pellucid, amplexicaul, ovate-acuminate or 

 lanceolate. Spikes shortly stalked, about fou?'-flowered,fiuallyreflexed. 

 Head of flowers small, globose. 



Zannichellia, (Linn.) Horned Pond-weed. 

 Linn. CI. xxi., Ord. i. 



Named in honour of John Jerome Zannichelli, a Venetian apothe- 

 cary and botanist. 



1, Z. ^afes^m, (Linn.) common Horned Pond-weed. Engl.Bot.t, 

 1844. Reich Icones, vii., 16. Locality. Ditches and stagnant water. 

 A. or P. Fl. May. Area, 1, 2, 3, 4, 5. Recorded in all the Districts. 

 Floating. Stems long, filiform, branched. Leaves opposite, linear, 

 entire, sometimes emarginate at the point. Flowers axillary, from a 

 membranous bractea. Fertile flowers upon a very short pedicel. 

 Style usually half as long as the fruit, sometimes six times shorter. 



This has been divided into several species or varieties, in various 

 ways, according as an author considered the style, stigma, fruit or its 

 stalk to yield the best characters, see Reichenbach PI. Grit. viii. f. 

 1003, 1006. 



ORDER. CYPERACE^. (JUSS.) 

 Cypeetis, (Linn.) Galingale. 

 Linn. Cl. iii., Ord. i. 

 Name. From Kyparos, (Gr.) a vase, or round vessel ; in allusion 

 to the form of the root. 



1. C. longus, (Linn.) long Cyperus, sweet Cyperus, English 

 Galingale. Engl. Bot. t. 1309. St. 52, 10. 



Locality. In marshes, but very rare. P. Fl. August. Area,**^*^ 



