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P L A T E DXL.
MESEMBRYANTHEMUM HETEROPHVLLUM.
Various-leaved Mesemhryanthemum.
CLASS XII. ORDER V.
ICOSANDRIA PENTAGYNIJ. Twenty Chives. Five PointaLs.
ESSENTIAL GENERIC CHARACTER.
CALYX 4—5-fidus. Petala numerosa, linearia,
basi coh?ereiitia. Capsula carnosa) infera.
polysperma.
EMTALEMENT 4—5-cleft. Petals numerous, linear,
and united at the base. Fruit flesh)',
below, many-seeded.
SPECIFIC CHARACTER.
MESEMRRYANTHEMUM octogynum, caulescens:
tbliis sub-semiteretibus, elongatis, obliquis,
nitidis, basi connatis : apicibus vel aduncorostratis
vel aiicipitibus, integris, obtusis.
Habitat in Promontorio Bonae Spei.
MESEMERYANTHEMUM eight-styled, with astern,
and leaves nearly half-round, elongated, oblique,
shining, and united at the base, with
the points either like a hooked bill, or twoedged,
entire, and blunt.
Native of the Cape of Good Hope.
REFERENCE TO THE PLATE.
1. A flower divested of the petals cut open.
2. Seed-buds and pointals, a summit magnified.
3. A dry capsule.
4. The capsule as it appears when half expanded in water.
5. The same when fully expanded.
OF tills fine Mesembryanthemum we have found no figure nor description. It is most allied to M. difforme,
so well illustrated by Dillenius, and figured before by Plukenet; but the figure of Miller,
tab. 12Ö. fig. 2, quoted for tlie same plant in the four last editions of the Species Plantamm, is certainly
M. dolabriiorme, as the author himself says, although his editor here has not stuck close to his text.
M.heterophyllum is very distinct from either, is a free growing species, and flowers from June to September,
the blossom open early in tlie morning, and shut in the afternoon. It is propagated both by seeds
and parting the roots. The fruit is divided into eight loculaments for the seed, separated longitudinally
by double elastic partitions, which are reflected above, so that the edges come in contact together and
cover the seeds. Eight elastic valves attached to the margin of the fruit, and adhering firmly to the
part containing the seeds, and to one another until mature, again enclose these. Two cartilaginous coloured
bodies, jointed near the base, and arising from the outer edge of the partitions, are promTnent upon the
interior of each of those valves, which have their edges always more or less reflected to facilitate the
entrance of moisture to the seeds, above which they continue to lie close so long as the atmosphere
continues dry : but, when it rains, or water is poured upon them, it enters by the openings betv^een the
valves, and is imbibed by the receptacles of tlie seeds and cartilaginous partitions, which presently become
much dilated, and the diameter of the firuit is considerably increased. The upper valves also by
this extension are drawn outwards, and being pressed at the same time by the edges of the partitions,
resting against the elastic rigid bodies on their interior surface, gradually rise to be perpendicular upon
the margin, when the fi-uit somewhat resembles a little cup with a Vandyke edge; but this is of short
duration, as the less elastic and hygrometrical exterior of the valves (for their interior parts imbibe
water and dilate rapidly) soon draws them backwards into the form of a star or polypetalous flower
with colours as vivid as if really vegetating. The edges of the partitions now become more erect^
leaving the seeds uncovered; and the water being led towards the ccntre by channels in the valves',
and retained by an elevated margin, the seeds are floated out of their cells. The fruit when dry, again
contracts as before, and the experiment may be repeated ad libitum. What a wonderful oeconomy of
Nature to produce the seeds just at the moment proper for their germination, and preventing them
until that time from falling on the parched sands and rocks upon which those plants vegetate! In
some plants, natives of cold regions, where seeds are in danger of perishing by moisture, and thei'e is seldom
sufficient warmth for their vegetation, an (Economy the direct I'everse takes place. The cones of
pines, being most hygrometrical externally, close firmly in moisture, and expand only in dry heat! The
singular qualities of the fruits of Mesembryanthema, we find first mentioned by Dillenius—¿e hü
Horlus Eltkammsis, vol. ii. p. 23/. It has since been noticed by Dr. Sims, who has described the fruit
of M. pinnatifidum in the Medical Journal for 1799, and also by Mr. König in the Annals of Botany,
but we believe no elucidation of the phEenomenon has been given before. Dr. Hägen, a German, who
possessed the fruils of three species without knowing what they were, imagined they were the whole
plants, and described them as a new and extraordinary reviviscent genus in Cryptogamia. Otliers have
taken them for the Rose of Jericho, which is not a fruit, but a plant. The fruits of most Mesembryanthema
exhibit the same metamorphosis, but with great variety. M hispidum has the upper valves
double, the inner membrane beautifully transparent. The fruit of this perfectly ripened, if put into
tepid water, will fly open as if with a spring. We have made experiments with the fruits of M. latum,
scalpratum, cordatum, and pugioniforme, all of which are very fine.
Our specimen is from the collection of A.. B. Lambert, esq.
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