166 Botany. 



1565. ACORUS calamus, L. (SWEET FLAG), 67, P. An alien 



aquatic, frequently planted. Fl. protogynous with aromatic 

 scent ; never ripens its fruit in Europe, perhaps due to the 

 absence of suitable insects. 



N.O. 2. LEMNACEM. 



(442) LEMNA, L. (DUCKWEED). Free - swimming leafless 

 aquatics ; the flattened-out floating part is stem. 



1566. L. trisulea, L. 6, A. Common. 



1567. L. minor, L. 6 7, A. Very common. 



1568. L. gibba, L. 68, A. Frequent. 



1. Plumstead Marshes. H. 



2. Charlton Marshes ; pond at Eltham. Dod. 



3. Higham Marshes, Cliffe. Dod. 



1569. L. polyrhiza, L. Flowers never seen in Britain. 



1. Plumstead Marshes. Reeves. 



2. Crossness Marshes ; pond by E. Wickham Church. Dod. 



3. Between Northfleet and Greenhithe. Jackson. 



4. Hayes Common, '94, Sc. ; '04, F.M.R. 



5. Pond in meadow adjoining Farnborough Common, 



'03. W.H.G. 



1570- WOLFFIA arrhiza, Wimm. (MICHELII, Sch.) ; the smallest 

 flowering plant in the world ; fls. never seen in Europe. 

 Local ; no records for our district, but easily overlooked. 



ALLIANCE V. PRINCIPES (often united to the SPADICIFLOR^:) . 

 N.O. 1. PALMACEM. (Palms.} 



ALLIANCE VI. GLUMIFLOR^E. 



N.O. 1. CYPERACEJE. Grass-like marsh plants; flowers 

 generally protogynous, wind -pollinated ; embryo im- 

 bedded in endosperm ; in the Grasses it lies outside. 



(458) ELEOCHARIS, Br. (under SCIRPUS, B.). 



1623. E. palustris, Br. 6, P. Wet places ; common, especially on 

 turfy moors. 



1. Swanscombe Marshes, '01. W.H.G. 



