43 8 
LEITNERTA CEAE 
Leitneria. Shrubs with spikes of dioecious firs. S fir. naked with 
3 — 12 sta. ? with scaly perianth and i cpl. and long style. Ovary 
i-loc., with i amphitropous ovule. Fruit drupaceous. Seed albu- 
minous. Embryo straight. Placed in Unisexuales by Benth. -Hooker. 
Leitnerieae (Benth. -Hooker) = Leitneriaceae. 
Lemna Linn. Lemnaceae. 6 sp. cosmop. ; 4 in Brit, (duckweed). 
The plant consists in most sp., e.g. L. minor L., of a flat green blade, 
floating upon the water; this is the stem, which performs leaf- 
functions. From the under side hangs down a long adventitious root, 
with a well-marked root-cap. There are no leaves. The stems are 
oval and slightly turned up at the ends, so that if two are placed near 
together in water, they will run against one another and adhere by 
the tips. In the posterior portion on either side is a groove under 
the edge. In this arise branches which may either (as in Z. trisulca 
L., &c.) remain in union with the parent shoot, or become detached 
and give rise to new plants. In autumn a number of these are formed 
ready to start growth in the next spring, whilst the mother plants 
sink to the bottom. The firs, are also borne in these grooves. There 
is a very reduced spathe, with 2 male firs, (each reduced to 1 sta.) and 
1 female (1 cpl.). 
Lemnaceae. Monocotyledons (Spathiflorae). 3 gen. with 18 sp. of 
free-swimming perennial water-plants with no leaves. The descrip- 
tion of Lemna applies to the other genera also. Firs, unisexual, 
monoecious; J of 1 sta., ? of 1 cpl., with 1 — 6 basal, erect, ortho- 
to ana-tropous ovules. The micropylar end of the inner integument 
forms a kind of lid upon the seed. Endosperm slight. The L. are 
regarded as very reduced Araceae (q.v.). Benth. -Hooker place them 
in Nudiflorae, Warming in Spadiciflorae. Genera : Spirodela, Lemna, 
Wolffia. See Nat. Pfl. for full details. 
Lennoaceae. Dicotyledons (Sympet. Ericales). A small order (3 gen. 
5 sp.) of S. Californian and Mexican plants, parasitic by their roots 
on roots of Clematis, &c. For details see Drude in Nat. PJi. Genera: 
Pholisma, Ammobroma, Lennoa. 
Lens (Tourn.) Linn. Leguminosae (ill. 9). 6 sp. Medit., W. As. Z. 
esculenta Moench ( Ervnm Lens L.) is the lentil, a food-plant of great 
antiquity. The seeds furnish a flour which is often sold at high 
prices as food for infants &c. under fancy names. 
Lentibulariaceae. Dicotyledons (Sympet. Tubiflorae). 5 gen. with 
250 sp. cosmop. All belong to the group of insectivorous plants and 
show many interesting features in their vegetative organs ; for details 
see p. 177 and genera. The infl. is usually a raceme or spike; firs, 
solitary in Pinguicula &c. Fir. g , zygomorphic, 5-merous. K 2 — 5- 
lobed, the odd sepal posterior, often 2-lipped, persistent on the fruit; 
C (5), 2-lipped, the lower lip more or less spurred ; A 2 (the anterior 
pair), epipetalous, with i-loc. anthers; £(2) i-loc. with free-central 
placenta and sessile 2-lobed stigma (the posterior lobe abortive) ; 
