116 
Monocotyledons with Petaloid Flowers — Naiadecz. 
INFLORESCENCE a pedunculate spike as in Pondweed ; or axillary and sessile as in Horned Pondweed (Zanni- 
chellia); or inclosed within a narrow sheath near the base of the leaves in Grasswrack. 
Stamens various; pollen in Grasswrack narrow-linear, with but a single membranous coat. 
USES, &c. Grasswrack (Zostera marina ), common on sandy shores of Britain, is collected and dried for use in 
packing goods, and stuffing mattresses. The Lattice-leaf ( Owvirandra) of Madagascar, a near ally of this Order, 
remarkable in its perforated lace-like leaves, is occasionally cultivated in warm tanks. Several British species are 
suited for parlour cultivation in aquaria. 
Natural Order 
ALISMACEAL Tab. 91. 
Diagnosis. Herbs, growing in water or in wet places, with radical leaves. 
Flowers with a 6-leaved perianth; usually perfect. Stamens hypogynous. 
Pistil apocarpous, or carpels at length separating. Seed exalbuminous. 
Distribution. A small Natural Order, generally dispersed in the four quarters of the Globe. 
Number of British Genera, 6 ; Species, 9. 
PERIANTH usually with the inner whorl coloured ; the outer in Water Plantain (Alisma Plantago ) sepaloid. 
Stamens as many as perianth-leaves in Water-Plaintain, or 9 in Flowering Rush (. Bntomus ). 
R s |^ EEDS solitary in each carpel in Water-Plantain, indefinite and scattered over the walls of the ovary in Flowering 
USES, &c.—None of the species are of much importance to mankind. Flowering Rush is an ornamental 
aquatic, occasionally planted on the margin of ponds. The rhizomes of some Asiatic species of Saqittaria afford a 
farinaceous food. 
