1101 



doubled on the paper with the same facility as other British grasses. 

 The best time for collecting the Leersia is towards the middle of Sep- 

 tember, which is, I think, the average season of flowering with us, but 

 as only a very small portion of the panicle is usually protruded in this 

 country from the top of the sheaths, it is difficult to ascertain when 

 the flowering actually begins ; I suspect it often commences in Au- 

 gust, and the seed is ripe in October. The roots are easily pulled up 

 out of the soft mud by grasping the culms at bottom, and come up 

 in huge, matted clumps, which are readily cleansed by l-epeated 

 plunging in the stream ; the superfluous water should then be wrung 

 out, and the mass divided into portions as large as can be conveniently 

 packed in the collecting-box. In this way only can specimens be 

 preserved in a perfect condition for drying, on the return home of the 

 collector, or for transmission to distant correspondents. I do not 

 think it would be possible to collect the Leersia between the leaves 

 of a field portfolio, unless strapped together much tighter than could 

 be conveniently managed, to obviate involution. There is this ad- 

 vantage, too, in keeping the specimens with their roots thoroughly 

 wetted in a close tin vasculum for about twenty-four hours previous to 

 laying them out, that the panicles, I find, by the warmth and moisture 

 of the included air, partially make their egress from the tops of their 

 sheaths much more decidedly than when growing in their native wa- 

 ters, thus approaching closer to the normal state of the inflorescence, 

 as developed in the south of Europe. 



An opinion seems to have prevailed amongst some botanists of Ger- 

 many that Leersia oryzoides was introduced to the ponds and rivers 

 of that country from Italy (Phytol. iii. 682, note). The cause of this 

 idea I apprehend to be, that the grass was overlooked there in the 

 same way and for the same reason that it so long escaped detection 

 in England, — its clandestine mode of flowering in central Europe. If 

 not rare, it is at least a local species on the continent, and possesses 

 little or nothing in its general aspect to attract attention from the 

 passer-by. Mr. Borrer has remarked to me its great resemblance to 

 the barren shoots of Phalaris arundinacea, its common associate, and 

 to which genus it was even referred by Linneus, but may always be 

 distinguished from that common grass by the paler, yellowish or 

 brownish green of the leaves, not to mention their extreme roughness. 

 It is probable, however, that this resemblance may have contributed 

 in no small degree to veil it from observation, both in our own country 

 and on the continent. Schreber (Beschreib. der Giasen, 2ter th. s. 7) 

 says our Leersia was first discovered in Italy, by Padua, Verona, &c, 



