POLYGONUM Hydropiper.
Biting Perficaria.
OCTANDR1A Tngynia.
Gen. Char. Cal. coloured, in 5 fegments, permanent.
Seed folitary, fuperior, angular, invefted
with the calyx. Siam. and P iß . uncertain in
number.
Spec. Char. Flowers with fix fiamina, and ftyle divided
half way down. Leaves lanceolate, waved,
unfpotted. Spikes flender, drooping. Stem eredt.
Syn. Polygonum Hydropiper. Linn. Sp. P I. 517.
Sm. F I. B rit. 426. Hudf. 170. With. 379.
Hull. 85. Relh. 160. Sibth. 12,9. Abbot. 89.
Curt. Lond. fa ß . 1 . t. 26. '
Perficaria vulgaris acris, feu Hydropiper. Rati
Syn. 144.
W E have lately (t. 955) defcribed one plant diftinguiflied
by the name of Hydropiper on very flight grounds; the prefent
had obtained the fame denomination previoufly, on account
of its pungent tafte, caufed by an eflential oil which refides in
the dots fcattered over the herb, particularly the calyx, forming
a diftinguifhing mark of the fpecies. Mr.-, Curtis however
notes that thefe glandular pun&ures are fometimes wanting,
and therefore they cannot enter into the fpecific chara&er.
No plant is more common than this in ditches and watery
places. It-flowers in Auguft and September, and maybe
known from all the other common fpecies by its flender drooping
lax fpikes, its light-green leaves-, always deftitute of the
black fpot fo general in P. Perjicaria, t. 756. Its root is
annual, in whorls from the lower joints of the ftem. Calyx
whitifh, tipped with red, glandular as above mentioned. Stamina,
6 rarely 8. Style cloven full half-way down, rarely three-
cleft^ Stigmas blunt. jj _
Mr. Ciirtis firft well diftinguiflied from this the P. minus,
whofe leaves are flat (not waved), ftem more or lefs procumbent,
and ftyle fcarcely at all' divided.