of Irel. p. 9.; FI. Hibern. p. 269. — Lenticula palustris vulgaris , Vaill. Par. p. 
114. t. 20. f. 3. — Lenticularia media, et minor, Mich. Gen. p. 16. t. 11. f. 2, 3. — 
Lens palustris, Ray’s Syn. p. 129. t. 4. f. 1. — Johnson’s Gerarde, p. 829. 
Localities. —In stagnant water in ponds and ditches, everywhere. 
Ann al. — Flowers in June and July. 
Root a solitary fibre, with a calyptra-like extremity (see fig. 15). 
Fronds (see fig. 1.) numerous, collected together, floating on the 
surface of the water, egg-shaped or roundish, each about a line or 
a line and a half long, proliferous and gemmiferous (see fig. 2.), 
minutely cellular, nearly flat on the upper side, slightly convex on 
the under, with a depression in the centre, from whence the root 
proceeds. Flowers (see figs. 9 & 12.) monoecious, very minute, 
destitute of both calyx and corolla, and enclosed, 2 together (1 ste- 
rile and 1 fertile one), in a thin membranous, beautifully reticulated 
spatha or sheath, (see figs. 5 to 8.) which proceeds from a cleft in 
the margin of the frond towards the base (see fig. 4). Sterile 
Flower composed of 2 stamens only, their filaments thread-shaped, 
longer than the spatha, and terminated with a yellow anther of 
2 distinct, globular lobes, which open at the top ; grains of pollen 
(see fig. 1 1 .) yellow, roundish, covered with small points. Fertile 
Flower (see fig. 12.) a pistil only, with an egg-shaped germen, a 
cylindrical, short style, and a blunt, flattish stigma ; “ a frond and 
2 flowers thus constituting the whole of the plant.” Pericarpium 
(see fig. 14.) a utricle of a roundish shape, somewhat depressed on 
one side, externally cellular, crustaceous within, terminated by the 
permanent style, which, according to the observations of the Rev. 
G. W. Sandys, who favoured me with several sketches of the 
fructification of this little plant, in July, 1838, was always, in the 
specimens which he examined, bent at an angle. Seed solitary, 
horizontal, with its hilum directed towards the narrow end of the 
frond. 
This species of Ducks’-meat is common in most ports of Europe. With us 
there is scarcely a pond or ditch of stagnant water, where it is not to be seen 
floating on the surface, and often increasing so rapidly by means of gemmee or 
buds (see figs. 2 & 3.) produced from clefts in the margins of the fronds, as well as 
by seed, that it frequently becomes so crowded, as to form large dense masses, 
which entirety conceal the water on which they float. It is considered to possess 
the property of purifying the unwholesome air in marshy places, absorbing this 
air during the day, and exhaling oxygen during the night. — Ducks and geese are 
fond of it, and it affords nourishment and protection to a great variety of Infusoria 
and other interesting aquatic obj ects. — It appears to be very tenacious of life, as an 
instance is recorded of some plants of it being taken from a pond in July, 1797, 
dried for 4 or 5 hours in the sun, and then put into a small box and preserved, in a 
dry state, till the end of March, 1800 ; when they were placed in a glass jar with 
water, where they not only revived, but flowered in the following August. It also 
possesses great power in resisting decay, as is proved by a circumstaure which 
fame under the observation of that excellent naturalist, the Rev. W. T. Bree, of 
Allesley, near Coventry, and which is described in the 9th volume of Loudon’s 
Gardeners’ Magazine, p. 124. 
The Natural Order Pistiacr.'e is composed of floating monocotyledonous 
frondose plants, with 2 naked flowers, inclosed in a spatha, and appearing fiorn 
the margin of the fiond. 1 lie sterile flowers consist of a definite number of 
stamens ; the fertile ones of a 1 -celled ovary, with one or more erect ovules ; a 
short style ; and a simple stigma. The fruit is membranous or capsular, inde- 
hiscent, and )- or moie-seeded. 'I he seed has a fungus testa, a thickened 
indurated foramen; and the embryo either in the axis of a fleshy albumen, and 
having a lateral cleft for the emission of the plumule, or at the apex of the 
nucleus. — Lemna is the only British genus in the older. 
