38 ENGLISH BOTANT. 



SPECIES X._PO TAMO G ETON LUCENS. Liim. 



Plates MCCCCVIII. MCCCCIX, 



Stems stout, sparingly branched, the lower branches barren. 

 Leaves almost all alternate and submerged, indistinctly stalked or 

 subsessile, but not at all amplexicaul, ascending, flat, long, oblong-oval 

 or -elliptical or -obovate, narrowed into a more or less distinct petiole 

 at the base, acute or obtuse and apiculate or mucronate or with the 

 midrib oxcurrent, not hooded, more or less undulated and irre- 

 gularl}' finely serrate at the margins, especially towards the apex, 

 translucent, with 11 to 17 longitudinal ribs connected by numerous 

 transverse veins,and with a narrow band of elongate cancellate areola- 

 tion along the sides of the midrib ; upper leaves opposite, similar to 

 the lower ones, or more rarely stalked, floating, and of rather firmer 

 texture, but never ( ?) coriaceous. Stipules large, blunt, 2-A\'inged on 

 the back, subscarious, with numerous strong longitudinal fibres. Pe- 

 duncles terminal and axillary, rather short, very stout, thicker than the 

 stem, slightly thickened towards the apex in fruit. Sepals with their 

 lamina transversely roundish-rhombic. Fruiting-spike dense, cylin- 

 drical, many-flowered. Nuts olive, large, slightly acuminated, scarcely 

 compressed, nearly straight along the upper margin, semicircular and 

 not decidedly keeled on the back, terminated by a short beak forming 

 a continuation of the upper margin. Plant bright green or olive, retain- 

 ing its colour when diy ; the leaves somewhat shining. 



Var. a, genuinus. 



Plate MCCCCVm. 



Beich. Ic. n. Germ, et Helv. Vol. VII. Tab. XXXVI. Fig. 64. 

 Billot, Fl. GaU. et Germ. Exsicc. No. 2382. 

 P. lucens, Auct. Plur. 



Leaves distinctly stalked, apiculate or shortly mucronate, serrulate 

 at tlie margins. Peduncles about as long as the spikes or not more 

 than twice as long. 



Var. 3, acuviinatus. 



lldch. Ic. Fl. Germ, et Helv. Vol. VH. Tab. XI. Fig. G9. 



P. acumiuatus, Schiim. " Enum. Fl. Saclland, vol. i. p. 49." 1 rp^gj,^ Beicli 1 c. p 23. 



P. cornutum, "PresZ. Fl. Cecb. p. 37." J 



Leaves distinctly stalked, elliptical or strapshaped-clliptical or strap- 

 shaped, with the midrib excurrcnt into a lung soft t^pine ; margins of 



