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LEMNA polyrrhiza.
Greater Duck-weed.
DIANDRIA Monogynia.
Gen. C har. Calyx of one leaf. Corolla none. Capsule
superior, with several seeds.
Spec. C har. Leaves sessile, somewhat convex beneath.
Ropts clustered.
S vn. Lemna polyrrhiza. Linn. Sp. PI. 1377. Sm. FI.
Brit. g 58. Duds. 399- With. 4 4 . Hull. ed. 2.
266. Reth. 359. Sibth. 15. Abbot. 199.
Lenticula palustris major. Dill, in Raii Syn. 129.
t. 4 . ƒ . 2. Haill. Par. t. 20. f . 2.
Lenticularia major polyrrhiza, inferne atro-purpurea.
Mich. Gen. 16. t. 1 1 . f . 1.
T H O U GH so very common on the surface of ditches and standing
pools, in the summer months, and though presumed to be an
annual plant, the flowers of this species of Lemna alone have
never been detected in Britain. Those of the other three we
have figured, but are obliged to exhibit this without fructification.
It is, we believe, the only plant so. circumstanced, (except a
very few of the class Cryptogamia,) throughout the present work.
Even Micheli sought the flowers of this Lemna in vain, though,
as he tells us, he very often bestowed the utmost attention in
looking for them. A German named Graver is alone recorded
by Wiggers as having found them, situated where the leaves
overlay each other, the fruit being larger, and more compressed,
than in L. gib ha, 1. 1233.
The plant before us is much larger than gibla, or minor, 1. 1095,
and essentially distinguished by the radical fibres growing many
together in a cluster, from the centre where the leaves unite.
The upper side of each leaf is level, obscurely striated or ribbed,
dark-green; the under purple, and rather convex.
We would, by all means, remove this genus from Moncecia.