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Hooker in Linn. Trans. v. 10. t. 31, f. 1. Schwaegr.
(for the fruit). Bridel, partly? Hook. and Taylor. A. rupestris var. gigantea Swartz in Herb. Turner.
Jungermannia alpina Linn. Dill. Musc. t. 73. f. 39. var. B. stems slender ; leaves lax, pale. (var. y. of Hooker
and Taylor.) Hab. Alpine rocks. var. B. on Ben Nevis, 1808, Hooker and Burrer.
Fr. May, June. Stems 1–3 inches in length, densely cæspitose; branches fastigiate, an inch long, or more. Leaves imbricated, spreading, appressed when dry, larger on the fertile shoots than on the barren branches, reddish or purplish brown, sometimes blackish, glossy when dry, obovateacuminate, and somewhat panduriform, areolæ dot-like, small. Perichạtial leaves large, sheathing, convolute. Stalked receptacle (or pseudopodium of Bridel) somewhat longer than the perichætium, bearing the abortive archegonia near the top. Capsule sessile, or with its short pedicel wbolly included in the vaginula at the top of the receptacle, 4-valved, the valves widely gaping when dry. Inforescence apparently dioicous; antheridia 7 or 8, mixed with long reddish filiform paraphyses, which are of firmer texture than usual in other mosses.
This species has been much confounded, by Weber and Mohr and others, with the next species. The figures and description of Dillenius doubtless belong to this moss.
2. Andreæa rupestris Linn. Hedw. (rock Andræa); stems short, with fastigiate branches; leaves imbricated, spreading from a sheathing base, subsecund, ovate or ovate-subulate, rather obtuse, papillose, nerveless; perichætial leaves large, ovate-lanceolate, convolute. (TAB. VIII.)
Andreæa rupestris Hedw. Sp. Musc. t. 7. f. 2. (fig. not
good). Schwaegr. Eng. Bot. t. 1277. Hooker in Lin. Trans. v. 10. t. 31. f. 2. Web. ‘and Mohr, Bot. Tasch. t. 11. f. 5, 6. Funk, Deutsch. Moose, p. 9. n. 6. Moug.
and Nestler, n. 115. Bridel. Hook. and Taylor. A. alpina Web. and Mohr, Bot. Tasch. t. 11. f. 3, 4.
Funk, Deutsch. Moose, t. 6. n. 1.
Jungermannia rupestris Linn. Sp. Pl. 1601. Hab. On subalpine rocks, frequent.
Fr. May, June. Stems about 4 inch in height, growing in incoherent tufts, sparingly branched. Leaves erect, and somewhat sheathing below, spreading above, frequently but not constantly secund, appressed when dry, narrowly ovate, somewbat tapering or subulate above, rather obtuse, papillose at the back; areolæ dotted; colour reddish-brown. Perichætial leaves larger, convolute. Capsules similar to the last, but smaller and paler.
This species is known from the preceding by its smaller size, and by its obtuse rufous and papillose not glossy leaves, which are also frequently secund. A variety with narrower and longer leaves was gathered near Newcastle by Mr. Thornhill and Mr. Robertson.
Dillenius, as appears from his remark, “in rupibus surculi e fusco. rufescunt,” considered this to be a variety of the preceding species. The figure given by Weber and Mohr, being magnified to thrice the natural size, has probably tended to mislead.
A. acutifolia Hook. fil. and Wils., a South American species, differs in its larger size and very acute leaves. A. mutabilis Hook. fil. and Wils., is an intermediate species, with narrower and more erect leaves than A. rupestris. A. nitida Hook. fil. and Wils., has ovate-oblong obtuse leaves, reflexed in the margin, and is a very distinct species. A. subenervis Hook. fil. and Wils., from the Andes of Quito, &c., is a large and beautiful species, with distant, oval or roundish, flaccid leaves.
b. Leaves nerved. 3. Andreæa Rothii Roth, Web. and Mohr. (black falcate Andreæa); stems short, sparingly branched ; leaves loosely imbricated, falcato-secund, subulate from an ovate base, with a broad thick nerve continued to the apex; perichætial leaves larger, elliptic-acuminate, convolute. (TAB. VIII.)
Andreæa Rothii Web. and Mohr. Bot. Tasch. p. 336. t. 11.
f. 7, 8. Schwaegr. Suppl. t. 106. (badly coloured, and much too pale). Hooker in Lin. Trans. y. 10. t. 31. f. 3. Eng. Bot. t. 2162. Moug. and Nestl. n. 116. Funk,
Deutsch. Moose, t. 6. n. 3. Bridel. Hook. and Tayl. A. rupestris Bridel, Meth. Musc. Turner. Wahlenberg.
Smith, Fl. Brit. Dill. Musc. t. 73. f. 40. Hab. On subalpine or alpine rocks, common. Fr. May, June.
Stems scarcely 4 inch in height, often less, incoherently tufted. Leaves falcato-secund, rigid, lurid, almost black, ovate at the base, the subulate prolongation twice as long, the nerve thick and predominant above. Perichætial leaves larger and convolute. Capsules as in the preceding:
Andreea Grimsulana of Schimper is a variety of this, with less falcate lanceolato-subulate leaves. A. crassinervia of Bruch seems to be another variety, with a thicker nerve. A. falcata of Bruch and Schimper is a distinct but allied species, with longer and more attenuated leaves and larger hexagonal areolæ. A. subulata of Harvey, from the Cape of Good Hope, has longer and more falcate leaves than A. falcata, and A. perichætialis Hook. fil. and Wils. has still longer leaves slightly falcate, and the perichætium less conspicuous.
4. Andreæa nivalis Hooker (tall slender Andreæa); stem elongated, slightly branched ; leaves loosely imbricated, subfalcate, secund, lanceolato-subulate, nerved to the apex; perichætial leaves similar to the rest ; capsule immersed. "(TAB. VIII.)
Andreæa nivalis Hooker in Lin. Trans. v. 10. p. 395. t. 31.
f. 4. Eng. Bot. t. 2334. Hook. and Tayl. Schwaegr.
Suppl. t. 248. Bridel. Hab. Alpine rocks, about the limit of perpetual snow. Rocks
at the highest summit of Ben Nevis, Scotland, at the eastern end. Plentiful on Ben-y-mac-duich, and on other mountains of the Cairn Gorm range.
Stems 2 or 3 inches long, cæspitose, slender. Leaves lax and distant, subfalcato-secund, incurved not appressed when dry, narr
arrowly lanceolate, tapering, acute, somewhat carinate, nerve narrower and more defined than in the last, continued to the apex; colour of the foliage pale reddish-brown; texture thinner and less opaque than in the preceding. Pericbætial leaves lax, not sheathing nor convolute, narrowly lanceolate, somewhat larger than those of the stem. Capsule not rising above the perichætial leaves, small; the pedicel or receptacle often shorter than the capsule. Inflorescence dioicous; barren. flower buds large, with numerous antheridia.
A very distinct species, in aspect approaching to Jungermannia juniperina.
ORDER II. SPHAGNACEAE.
2. SPHAGNUM Dillenius. Bog Moss. The Sphagna differ from all other known mosses in the fasciculate insertion of the branches, in the structure of the leaves, capsule, and antheridia, and in the absence of proper roots.
Perennial, aquatic, or amphibious plants, growing in dense patches, usually of a whitish colour, in some species occasionally reddish or lilac. Stems simple, or forked, or sometimes branched and fastigiate, erect, the internal tissue almost woody, coated with one layer or usually with several concentric layers of large membranous cells. Branches disposed in fasciculi of 3, 5, or 7, the fascicles spirally inserted in a quinquefarious manner, at first short, subclavate and erecto-patent, subsequently elongated, widely spreading, and recurved, the lower branches of each fascicle attenuated, pendulous, and closely applied to the stem. Leaves quinquefarious (disp. ), those of the stem obliquely inserted, erect, spreading or deflexed, ovate, more or less obtuse; branch-leaves more crowded, concave, roundish, ovate, or lanceolate, nerveless, curiously reticulated, the principal cellules lined (in all but one exotic species) with spiral or annular filaments, perforated (chiefly at the back of the leaf) with minute pores, communicating also with each other by intercellular pores ; the network of the leaf constitutes the real parenchymatous tissue, and is formed of narrow elongated cellules without pores, more or less filled with chlorophyll. Inflorescence monoicous, or dioicous. Antheridia roundish, like those of Jungermannia, pedicellate, inserted singly amongst the perigonial leaves (which are usually coloured) at the clavate extremity of short ramuli. Fertile flower at first sessile, occupying the place of one of the upper ramuli, in the axis of a fascicle: as the fructification advances, the receptacle elongates, and the perichætial leaves becoming separated from each other, it presents the appearance
of a lateral branch; hence the genus is cladocarpous, though in the first stage it seems rather to be pleurocarpous. Perichatial leaves at length much larger than the rest, sheathing and convolute. Archegonia about 4 together, without paraphyses. Capsule globular, sessile on the turbinate fleshy vaginula, within which the bulb-like pedicel is enclosed; sometimes, though rarely, two capsules occur on the same receptacle. Peristome none. Lid flattish. Calyptra entirely surrounding the ripe capsule, ruptured near the middle, the lower part persistent and continuous with the apex of the vaginula. Columella abbreviated, not rising so high as the mouth of the capsule. Spores small, at first clustered, four together.
This singular genus was considered by Bridel and the authors of the Bryologia Germanica, to be destitute of a vaginula, and was accordingly referred to a separate order. It agrees in this respect with Andreæa ; and in the structure of the antheridia it presents a strong analogy to the Hepatica, between which and the true mosses, Sphagnum and Andreæa may be regarded as intermediate links. The name Sphagnum was first used by Pliny for some kind of moss that grew upon trees.
Mr. Valentine has given a very accurate account of the structure in Musci Nottinghamienses. The true cellular parenchymatous tissue is correctly stated to be derived from the elongated interior tubes of the stem. The function of the larger air-cells is not yet fully understood ; but they may serve instead of roots, which are entirely absent from the full-grown plants. Designed, as the Sphagna are, to fill up water pools in bogs, which they do in a very short space of time, roots are unnecessary, and when at length, from increase of bulk, they emerge from the watery element, an admirable provision for the continued supply of moisture is secured by the densely crowded stems having their pendulous ramuli so applied to their surfaces as to ensure the capillary attraction upwards of the moisture from below. The debris of the plants, the growth of former years, is perfectly indestructible by moisture. In some favourable sections of peat mosses, exposed by the diggers for peat, strata of bog.moss, several feet or even yards in thickness, may be seen, very little changed in appearance or colour ; they mark the site of formerly existing pools of water, and the peat there found is rejected, as being too light and spongy for the purpose of fuel.
In this family the leaves and the fascicles of branches are disposed around the stem in spirals, so that for every complete spiral formed by five fascicles of branches, there are eight spirals formed by twenty leaves, four leaves being inserted between each pair of fascicles. The insertion of the fascicles, like that of the antheridia, is not in the axils of the leaves, but immediately at the side of the leaf, presenting some analogy to Fontinalis.
After close and extensive observation of the species in their places of growth, it is believed that they do not owe their characters to any local or adventitious influences. It is not uncommon to find three or more species growing intermixed; though some are confined to peat mosses in parts which have never been disturbed by the spade. The definitions of the species in works already published are unsatisfactory; little reliance can be placed on the length of the pedicel of the fruit, or on the number of the branches in a fascicle. In the determination of the species, we have availed ourselves of the differences of form and structure presented by the leaves; those of the stem and of the perichætium being especially important in one or two species. The structure and form of the utricles, constituting the external tissue of the branches, are also of great service in a few other cases. In general, the species are easily recognised by their habit. Of the nine species described in this work two are undescribed in Bridel's Bryologia Universa. It is remarkable that in the same locality, and in precisely similar circumstances, six of the species are constantly pale, without any tinge of red, while three species, S. cymbifolium, acutifolium, and rubellum, are frequently of a reddish hue.
Bridel describes the lid “cum crepitu desiliens ;" and this is confirmed by Mr. Thomas Lyle of Airth, and subsequently by our own observation. The capsule in drying contracts strongly, and, by the pressure, the lid is at length driven off with considerable force, accompanied with an audibly explosive sound, to the distance of seven inches or more; the spores also are ejected at the same time, either by the explosion of the compressed air, or by their own elasticity.
The structure of the contents of the anther is very curious, and was first well observed by M. Unger. At the period of inflorescence, (from October to March,) the anther bursts at the apex. It is filled with minute bodies (spermatozoides of M. Schimper) consisting at first of hemispherical cellules, whose diameter is aboutz: oo of an inch. These, when the anther is ripe, present to view a spirally coiled fibre of one turn and a half, attached to one end of an opaque-greenish corpuscle, shaped like a sausage, with a constriction in the middle, changed to blue on the application of tincture of iodine. These corpuscles with their spiral fibres, exhibit in water a great variety of movements. Their progressive motion is usually effected by gyrations in the direction of the axis of the spiral, the spiral acting as a screw to draw the corpuscle through the fluid. These movements continue for soine minutes, and with different degrees of velocity, sometimes slow, at other times very rapid, and seem to be the effect of a small jet from an orifice in the corpuscle, the jet being probably caused by the action of endos
We cannot agree with those authors who consider these corpuscles to partake of the nature of animalcules. When dry,