DROSERA ROTUNDIFOLIA. ROUND-LEAVED SUN-DEW.
DROSERA rotundifolia; foliis orbiculatis radicalibus, scapo racemoso.
DROSERA rotundifolia. L im . Sp. PI. p. 402. Iluds. Angl. p. 135. Light/. Scot. p. 175. With. Boh Arr.
ed. 4. vol. 2. p. 319- Fl. Dan. t. 1093. Hoffm. Germ. ed. 3^ vol. I. P. t. p. 152. Willd. Sp. PI.
vol. l .p . 1543. Smith Fl. Brit. p. 546. Engl. Bot. t. 867. Decand. Fl. Fr. ed. 3. vol. 4. p. 728.
Fl. Gail. Syn. p. 384. Pers. Syn. PI. vol. 1. p. 336. Aiton Hort. Kew. ed. 2. vol. 2. p. 189.
Wahl. Fl. Lapp. p. 74. Pursh Fl. Am. Sept. vol. 1. p. 210. Hook. Fl. Scot. P . I. p. 98.
RORELLA foliis petiolatis subrotundis, caule nudo paucifloro. Hall. Helv. n. 834.
ROS soils folio rotundo. Rosa-solis, or Sundew with round leaves. Rail Syn. p. 356.
ß. RORELLA rotundifolia perennis. Perennial round-leaved Sun-dew. Rail Syn. p. 356’.
Class a n d O r d e r . PENTANDRIA HEXAGYNIA.
[N a tu r a l O r d e r . DROSERACEÆ, Decand., Hook. CAPPARIDIBUS AFFINIS, Juss., Decand. in FI. F r.]
Ch a r . O r d . N at. Cal. quinque-fidus persistens. Pet. quinque, æqualia, subunguiculata, marcescentia. Stam. definite.
Anthera Stylique æstivatione involutæ. Ovarium uniloculare, polyspermum. Capsula unilocularis semi-tri-quinque-valvis,
polysperma. Semina minuta, arillata. Embryo minuta ad basin alburainis carnosi immersa. Radicula hilo opposita.-li
Het'ba. Folia plerumque radicalia, glanduloso-pilosa.
G e n . Ch a r . Cal. qumque-fidus. Pet. quinque. Styh sex. Caps, unilocularis, tri- vel quinque-valvis, polysperma.
G e n . Ch a r . Cal. five-cleft. Pet. five. Styles six. Caps, one-celled, from three- to five-valved, many-seeded.
Ra d ix perennis, parva, fibrosa, fusca.
Folia omnia radicalia, in orbem expansa, petiolata, orbicu-
lata, vel orbiculato-reniformia, fiavo-viridia (juniora
ruberrima), dorso paululum convexa, supra parum con-
cava, margine facieque superne pilis rufis longiusculis
apice glanduloso-viscosis tecta : Petiolus folio duplo
triplove longior, compressus, pubescens, versus basin
fasciculis tribus purpureorum pilorum instructus.
Sc API plerumque tres vel quatuor ex eadem radice, palmares,
erecti, purpurei, glabri.
R acemus terminalis, pauciflorus, primum cernuus, dein erec-
tus.
Flores albi, pedicellati, pedicello glabro ebracteato.
Calyx profunde quinquefidus, laciniis oblongis apice denti-
culatis.
Corolla pentapetala: Petalaoblongo-obovata,basiattenuata.
St am in a quinque, longitudine germinis: Filamenta com-
pressa, sursum paululum dilatata.
PlSTlLLUM: Germen obovatum, viride: Styli sex, sursum i
curvati, breves: Stigmata biloba, glandulosa.
Capsula oblonga, parva, ealyeem persistentem excedens, :
atque corolla marcescente tecta, nigro-fusca, semi- '
trivalvis, unilocularis.
Recepta culum e medio valvarum.
S em in a numerosa, minutissima, elliptica, fusca, lasvia, basi
apieeque mucronata, arillo fusco subopaco tecta.
A l bum en carnosum.
Embryo ad basin albuininis.
Fig. 1. Front view of a leaf. Fig. 3. Back view of the sam<
dular hairs of the leaves. Fig. 6. Calyx. Fig. 7. Petal. Fi,
lion of the Germen. Fig. 11. Capsule inclosed within the
which the calyx and corolla are removed. Fig. 13. One o
enveloped in the arillus. Fig. 15. Seed from which the
embryo.
Root perennial, small, fibrous, brown.
L eaves all springing immediately from the root, and expanding
orbicularly, placed on footstalks, of an orbicular,
or between a kidney and orbicular, shape, yellowish-
green,(the youngerones very red,)slightly convex on the
back, and a little concave beneath, covered on the
margin and upper surface with longish red hairs, which
are tipped with a viscous gland : Petiole twice or
thrice as long as the leaf, compressed, pubescent, furnished
at the base with three fascicles of purplish
hairs.
Scapes generally three or four from the same root, three or
four inches long, erect, red, glabrous.
Raceme terminal, few-flowered, at first nodding, afterwards
ere'et.
Flowers white, pedicellate, the pedicel glabrous and destitute
o f bracteas.
Calyx deeply quinquefid, its segments oblong, toothed at
the points.
Corolla of five petals: Petals between oblong and obovate,
attenuated at their base.
Stam en s five, of the same length as the germen: Filaments
compressed, a little dilated upwards.
P istil : Germen obovate,«green : Styles six, curved upwards,
short: Stigmas two-lobed, glandular.
Cap sul e oblong, small, longer than the persistent calyx, and
surrounded with the decaying corolla, blackish-brown,
valved half way down, one-celled.
Recepta cle arising from the middle o f the valves.
S eed s numerous, very minute, elliptical, brown, smooth, mu-
cronate at the base and point, covered with a brown
semitransparent arillus.
A l bum e n fleshy.
i Embryo placed at the base o f the albumen.
:. Fig. 3, 4. Young leaves not yet expanded. Fig. 5. Gians'
8. Pistil and stamens. Fig. 9. Single stamen. Fig. iO. Sec-
calyx and marcescent corolla. Fig. 12. Capsule burst, from
f the valves of the capsule, with the seeds. Fig. 14. Seeds
arillus is removed. Fig. 16. Section of a seed to show the
All the species of Sundew, and they are inhabitants not only of Europe, but of Asia, Africa and America, have the margins
of the leaves, and their upper surfaces, clothed with red pedunculated glands, from which exudes a pellucid glutinous
fluid, and which probably attracts flies and other small insects, and certainly retains them by its viscidity. Some botanists
however go further; and Roth, in his Flora Germanica, says, that the German species of the genus (which are the same as
ours) are endowed with irritability: and elsewhere, in his Beytrage, he says, “ With a pin I placed an ant upon the middle
of a leaf of the D. rotundifolia, but so as not to disturb the plant. The ant endeavoured to escape, but was held fast by
the clammy juice at the points of the hairs, which was drawn out by its feet into fine threads. In some minutes the short
hairs on the disk of the leaf began to bend, then the long hairs, and laid themselves upon the insect. After a while the leaf
began to bend, and in some hours the end of the leaf was so bent inwards as to touch the base*.”
Withering also mentions a Mr. Whately, who, observing some of the leaves folded up of the Drosera anglica, ascertained
that there was a dead insect in each ; and conceiving this duplication of the leaf to be owing to the insect, he was prompted
to irritate the leaf by touching it with a pin. The effect was, as he expected, a sudden contraction of the foliage upon the
pin.F
or my own part, I have never seen any thing of the kind. The young leaves, indeed, before expansion are beautifully
and curiously rolled in with a double curvature. The whole lamina or blade of the leaf (as represented at / g . 3) is bent
down upon the footstalk ; and the two sides (as at fig . 4.) are so completely involute as to conceal entirely the hairs and
glands with which the leaves are covered on their upper surface.
The genus Drosera will probably constitute an order by itself: Decandolle has formed of it the Droseracece; but I am
not aware that he has any where published his ideas of-t* e characters of the Order. Salisbury has, I believe, invented the
Nat. family of Droserete, intending to include in it t1 e Genus Diona,a, which, however it may accord with Drosera in
some particulars, is widely removed from it in otlv.s.
The present species is the most common of the three British ones, and is equally found in North America, inhabiting wet
and swampy places, such as are favourable to the growth of Sphagna. I am not aware that any species but the present has
the three pencils of hairs, which are seen on the lower part of the leafstalks.
D. rotundifolia is believed by many to be the cause of the rot in sheep; but its acrid and caustic nature is sufficient, one
would think, to prevent those animals from eating it.
It flowers in the months of July and August.