2805
POLYGONUM Raii.
Raian Knot-grass.
OCTANDR IA Trigynia.
Gen. Char. Cal. of 5 persistent segments. Cor. 0.
Stam. 5—8. Styles 2—3. Fruit a one-seeded
compressed or trigonous nut, with alateral embryo
and the cotyledons linear-oblong.
Spec. Char. Stem procumbent, herbaceous; ochre®
2-lobed, ovate acute, at length torn, with few unbranched
distant nerves j flowers axillary ; fruit
very smooth and shining, much longer than the
peryanth.
Syn. Polygonum marinum. Ray Syn. 147. (Excl.
Syn.)
P. aviculare (3 maritimum. Huds. FI. Ang. 1. 171.
(Excl. Syn.) Sm. Eng. FI. 2. 238.
P. Roberti. Lois. FI. Gall. ed. 2. t. 1.283.?
P. aviculare (3. Hook. Brit. FI. ed. 3. 185.
P. Raii. Bab. in Linn. Trans. 17.458.
P. acetosum, Hook. Comp, of Eng. Flora, ed. 2.,
not Biberstein FI. Tauro Cauc. 1.304.
T h i s plant, which has been considered as a variety of P .
aviculare, may always be distinguished from that species by
observing the fruit, which in this is always quite smooth and
shining, and protruded far beyond the peryanth. In all the
varieties of P . aviculare it is found to be granulate-striate
and quite hidden by the peryanth. Our plant has its ochreas
two-Iobed, ovate, acute, entire when young, much shorter
than the internodes, and having about two distant unbranched
nerves. The leaves are lanceolate, with the margins
of the younger ones revolute. The stem prostrate,
not much branched, ribbed, often spreading for several feet
over the loose sand, in which it always grows.
There is a maritime variety of P. aviculare which exactly
resembles this plant in appearance, but its fruit differs