514 NAIADACEAE 



D. Alisma is not recorded for Oxfordshire, Wilts, or E. Gloucester- 

 shire, but is found in Buckinghamshire, Surrey, and Hampshire. 



BUTOMUS, Linn. Gen. n. 455 (Tournefort, Inst. t. 143). 

 B. umbellatus, Linn. Sp. PI. 372 (1753). Flowering Rush. 



Top. But. 411. Syme. E. B. ix. 76, t. 1443. Nyman, 678. Fl. Oxf. 279. 

 Native. Paludal. By streams and brooks. Locally common, but 



perhaps diminishing in frequency. P. June-July. 

 First record. The Loddon, Mr. S. Budge, 1800, in Herb. Brit. Mus. 



Published by Dr. Noehden and Mr. Bicheno in Maxofs Agr. Berks, 



1809. 



1. Isis. In the canal near Shrivenham. Near Kelmscott. Near 



Lechlade. Appleton. Wytham. At intei'vals in the Thames 

 fi'om the Cole to Oxford. Buckland Lake, Buscot Lake. 



2. Ock. l:ienr 0:s.{'ord, not nnconiiinou, Baxter in Purt, Midi. Fl. Iffley, 



Slc, Garnsey. Marchum, Walker. Denchworih, Wait. Day's Lock, 

 G. I). Leslie. North Hinksey, Bidlcij. Near Uffington in the 

 canal abundant, and also found at intervals along its course to 

 Abingdon. Ferry Hinksey, abundant. Kennington. Between 

 Radley and Abingdon in the meadow ditches. 



3. Pang. Tidmarsh, Tufnail. Moulsford. Pangbourn. Tilehurst, 



and between Tilehurst and Reading. 



4. Kennet. Northcroft, and other streams near Newbury, Bunny. 



Newbury, Reeks. In the peat pits near Newbury, Bicheno. 



Burghfield Meadows, Tufnail. Benham. Near Southcote. 

 Theale. Midgham. 



5. Loddon. Banks of the Loddon, Rudge. Pond at the foot of 



Cookham Down, Mill. Under Quarry Wood, Britten. Near War- 

 grave, Stanton. Near Eton, Byer. Hurley, Leslie. Sonning 

 Meadows, Tufnail. Near Albert Bridge, Home Park, Bolton King. 

 Bisham. Bray. Arborfield, &c. • 



' Near Abingdon we were gratified by finding this most elegant aquatic, 

 clumps of which were constantly occurring where the water was shallow, 

 either at the river-side or in siDots where the ground approached the surface 

 in mid-stream. It is by no means common to all the banks along the 

 Thames.' Hall's Book of the Thames, 132. 



The lighter green colour of the leaves, which are also shorter and narrower, 

 distinguishes this plant, when not in flower, from Sparganium. They are of 

 a more yellowish green than Panicularla {Glyceria) aquatica. 



Butomus umbellatus is found in all the bordering counties. 



NAIAD ACE AE, Lindl. Nat. Syst. ed. 2, 366 (1836). 



TRIGLOCHIN, Linn. Gen. n. 409 {Juncago, Tourn. Inst. t. 142). 

 T. palustre, Linn. Sp. PI. 338 (1753). Marsh Arrow Grass. 



Top. Bot. 412. Syme, E. B. ix. 65, t. 1433. Nyman, 680. Fl. Oxf. 281. 



