444 96. KAIADACE3J. 



2. EUP'PIA Linn. Tassel- Pondweed. 



1. R. marit'ima (L.) ; /?e^. /or**/ spirally twisted, anth.-cells 

 oblong 1^ times as long as broad, nut ovoid rather obliquely 

 erect E. B. 136. R. vii. 17. R. spiralis Hartm. Whole 

 plant stronger than the next. L. very narrowly linear, formed 

 as in Potamoqeton pectinatus. Sheaths large, inflated. Salt 

 marshes. P. Vii. VIII. E. S. I. 



2. R. rostelldta (Koch) ; ped. short not spiral, an th. -cells 

 squarish as long as broad, nut gibbous at base obliquely ascend- 

 ing when young. Sy. E. 23. 1428. R. vii. 17. Whole plant 

 very slender. L. rather filiform than linear. Sheaths small, 

 close. A very small form (nana Bosw.), with very short de- 

 curved ped., is found in Orkney. Salt marshes. P. VI. VIII. 



E. S. I. 



3. ZANNICHEL'LIA Linn. Horned Pondweed. 



1. Z. palus'tris (L.) ; style at least half as long as the diver- 

 gent nuts. E. B. 1844. Floating. L. slender, opposite, fili- 

 form. Fl. axillary, sessile. a. Z. brachystemon (Gay) ; fr. 

 2 4 subsessile with crenate back, style J length of fr., stigma 

 large crenulate, anth. 2-celled. /3. Z. macrostemon (Gay) ; 

 fr. 2 4 sessile rarely crenate, style | length of fr., stigma small 

 crenulate, anth. ^-celled. y. Z. pedunculata (Reich.) ; fr. 2 o 

 stalked muricate, style as long as fr., stigma large crenulate, anth. 

 2-celled. Sy. E. B. 1426. Z. pedicellata (Fr.). I doubt the 

 constancy of these characters. Stagnant water, y. Brackish 

 water. A. or P. V. VIII. E. S. I. 



2. Z. polycar' pa (Nolte) ; style scarcely of length of con- 

 verging sessile nuts,/r. 5 6 subsessile crenulate on back, con. 

 very ing , style scarcely \ length qffr., stigma large repand, anth. 

 2-celled. Much like Sp. 1. In water. Orkney 1 . Belfast. 

 A. V. VIII. S. I. 



Order XCVI. NAI ADAGES. 



Fl. moncecious or dioecious, in a spath. Perianth 0. Stam. 

 free, 1 3. Ovary 1, superior, with 1 ovule. Style 1 ; stigmas 

 2 4, filiform. Fr. a nut enclosed in the persistent spath, 

 1-celled, 1-seeded, not bursting. Albumen 0. Embryo with a 

 thin skin having a lateral cleft. 



1 Dr. Boswell referred the Orkney plant, with longer styles and less 

 conuiveut fr., to var. tenuissima (Fr.). H. & J. G. 



