NAIADACE^. 59 



Stems slender, branched. Leaves alternate and opposite, much re- 

 sembling those of Potamogcton eu-pectinatus, alternate, and having 

 the stipules adhering to the petiole of the leaf, so as to form a sheath, 

 as in that plant. Peduncles raising the spikes nearly an inch out of 

 the water when in flower, but afterwards twisting spirally, so as to 

 submerge the fruit, at length 2 to 4 inches long. Pedicels of the nuts 

 f to 1 inch long or even more. Nuts olive, -^- inch long, succulent and 

 green until completely ripe. Plant bright green, turning black in 

 drying. 



Greater Euppia. 

 French, Hiippie maritime. German, Mcerstrancls-Buppie. 



Sub-Species (?) II.— Ruppia rostellata. J^ocJi. 



Plate MCCCCXXVIII. 



neich. Ic. Fl. Germ, et Helv. Vol. VII. Tab. XVII. Fig. 25. 



Billot, Fl. Gall, et Germ. Exsicc. No. 655. 



R. maritima, Linn. Herb. 



R. maritima, var. /3, Hook. & Am. Brit. Fl. ed. viii. p. 485. 



Leaves linear-setaceous, with close-fitting sheaths. Peduncles very 

 short at the time of flowering, and scarcely raising the spike above the 

 water, at length about as long as or a little longer than the pedicels of 

 the nuts, flexuous. Anthers quadrate-orbicular, about as long as 

 broad. Nuts veiy obliquely ovate-ovoid, acuminated into a rather 

 short beak which forms a continuation of the outer margin of the nut. 



In brackish ditches and pools. Rather common, and generally dis- 

 tributed. I do not possess specimens from counties farther south than 

 Essex and Gloucester, but it occurs at Brading, Isle of Wight, and 

 Mr. H. C. Watson gives it as an inhabitant of Somerset. In Scotland 

 I have collected it in Ku-kcudbright, Haddington, and Orkney, and 

 Dr. Dickie states that it occurs in Kincardineshire, and at Banff, and 

 I have no doubt it is the plant generally reported as R. maritima, from 

 Scotland. In Ireland it is not unfrequent, and generally distributed 

 round the coast. 



England, Scotland, Ireland. Perennial. Summer. Autumn. 



Very similar to R. spiralis, but with narrower leaves and less 

 inflated sheaths, on account of the stipules being narrowed rather 

 suddenly a little above the base. The peduncles are much shorter 

 both in flower and fruit, and though flexuous, I have never seen them 

 curled into rings as in R. spiralis; the nuts are a little smaller and 

 very obliquely acuminated into a longer beak than that of the pre- 

 ceding form ; the anthers, too, are rounder. 



This plant appears to flower considerably earlier than R. spiralis — at 



