CLASS XXI. ORDER VII. ] SAGITTARIA. 1221 
and being overlooked as a small plant only instead of being so distinct 
a species. We found it several years since frequent about Lincoln, 
and Sutton-on-Trent, Nottinghamshire. 
3. M. verticilla'tum, Linn. (Fig. 1471.) Whorled Water Milfoil 
Flowers in terminal axillary whorls ; leaves whorled, pectinated, with 
setaceous segments 
English Botany, t. 218.—-English Flora, vol. iv. p. 143.—Hooker, 
British Flora, ed. 4. vol. i. p. 347.—Lindley, Synopsis, p. 110. 
Roots whorled, fibrous. Stem round, smooth, the lower part under 
water, with the whorls of leaves cut into fine capillary segments, the 
upper flowering part above the water, with the leaves having a 
broader somewhat dilated mid-rib, and the segments broader than 
those of the lower leaves. Inflorescence whorls of about four flowers 
in the axis of the upper leaves, sessile, inconspicuous, much shorter 
than the leaves. Stigmas four, spreading, thickly feathery Fruit 
a one seeded, sub-compressed nut. 
Habitat —Ponds and ditches; Norfolk, Cambridge, Cheshire, 
meadows near Nottingham, near Sheffield, Yorkshire, and Anglesea. 
Perennial ; flowering in July. 
This is a variable p!ant, from growing in pools, which, as they be- 
come partly dried up in the summer, leave the plant exposed, when 
part or the whole of the leaves become more dilated both in the mid- 
ribs and segments ; indeed, we have some specimens from Notting- 
ham meadows, which have the mid-rib so much dilated that the 
segments are only narrow teeth, and again other specimens from 
deep pools, with all the segments of the leaves drawn out into long 
capillary segments, the spike only appearing above the water, with 
its leaves more dilated. 
GENUS XXVITI. SAGITTA'RIA.—ILinn. Arrow-head. 
ENat. Ord. Atisma’cEz. Brown. 
Gen. Cuan. Barren flowers calyx of three pieces. Petals three. 
Stamens numerous. ertile flowers calyx of three pieces, petals 
three, ovaries numerous, on a globose receptacle. Capsules 
small, compressed, margined, single seeded—Name from 
sagitia, an arrow, from the shape of the leaves. 
1. S. sagittifo'lia, Linn. (Fig. 1473) Common Arrow-head. Leaves 
arrow-shaped, with straight lanceolate lobes, the scape simple. 
English Botany, t. 84.—English Flora, vol. iv. p. 144.—Hooker, 
British Flora, ed. 4. vol. i. p 347.—Lindley, Synopsis, p. 253. 
Roots fibrous, from a large globular fleshy tuber, and putting out 
bulbiferous runners, the whole plant smooth, with somewhat milky 
