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Show 102 The Hiflory of P L A N T S. It is frequent on the Alps and Pyrenrean mountains, nm: is wanting, in that &reat refource of the Moffes, Engla'nd : we have it on Mendip-hllls abundantly, and m fome other places. The more fingular fpecies, befide thefe, are, I. T_he ~ender, fiartop'd Bryum, with round heads. 2. The cruet-!haped Bryum ?f Dtllenms. 3. The fickle-leaved, bending Bryum. 4· The green, cluftery, Alpme Bryum •. 5· T.he Iong-ibanked curled Bryum. 6. The dwar( long-{hanked Bryum, wnh hatry leaves. 7. The branched Bryum, with pendulous heads. 8. The ibrubby. Bryum, with long tranfparent leaves. 9· The round, tranfparent-leaved Bryum, with pendulous he~ds. 1o. The fmall, brittle, whitilh Bryum. I I. The Norway Bryum, with a [cadet umbrella-head, 12. The membranaceous, blunt-leaved Bryum. M 0 S s E S. Clqfs the Fifth. Genus the Second. P 0 L Y T R I C H U M. P 0 L Y T RICH U M is a genus of Moffes, confifting of ftalks fur~ilhed with leaves, and producing feparate pedicles fupporting capfules. !he pedtcles always growing out of the extremities of the ftalks, an? the calyptrre, whtch cover the heads, being hairy the calyptrre of many of the fpectes are compofed merely of a downy matter and' frequently they are deeply dentated at the edges; in the other fpecies, tho' they a;e membraneous, they are thick covered with hairs. The leaves of fome of the fpecies are rigid, in others they are fofter; in fome they have a met?branaceous. a~pendage at their bafe, by means of which they embcace the ftalk; m others thts IS wanting. The pedic1es of the capfules, in this genus, are in ferted in to ~ t~be at their bafe, which is furrounded with membranaceous leaves. The capfules, m fome of the fpecies, are [quare, in others they are round: the fquare ones have an apoph~Gs at th~ir bafe, by which they are conneCted to the ~alk; the round ones have nothmg of th1s. The fummits of fome of the ftalks, wh1ch do not produce capfules, are ftelb ted. Thefe Linnreus calls the female plants, and the il:ellar part the female flower; but there requires a more perfeet ~ifcov.ery tha~ ha~ yet bee.n made of the fruCtification of thefe plants, in order to the determmmg this With certamty. The Polytricha, in their manner of growth, greatly emulate the brya. Some of them have no ftalks, but only a clufier of leaves at the ba(e; fame confift of fingle fialks, fome are ramofe in the manner of the bryum, from the growth of a fccond year's {hoot upon that of a former; in this cafe the pedicle arifes, as in the bryum, from the fummit of the laft year's ftalk, and feems therefore to arife from the fide of the plant, not from it's top. x. Polytrichttm Jimplex capfula quadrangulari foliis firratis. The /quare-headed Polytrichum, with Jerrated leaves. This is a ver.y tall and large Mofs, though it's ftem is of the fimplc kind. It grows to fix or eight inches in height; it's fialks are {hong and rigid, and it's roots confiderably long, fpo1~gy, and fibrous. Part of the fialk is ufually buried in the gronnd, and that has lhort £lender leaves, but {paringly fet on. The part that is above the furface has, on the contrary, much longer, larger, and clofer fet ones. They are of a dark, green colour, broadefi: at the bafe, and thence tapering to the point; and, when examined very nicely with the affifiance of a fmall magnifying glafs, they are found to be very finely ferrated round the edges; the ftalks fometimes break into two near the top, but it is very rarely. The pedicles of the' capfules arife from the center of the leaves that cover the top of the ftalk ; they are very robuft, and two inches or more in length, and are furrounded at the ba(e with a fet of leaves, broader, thinner, and more pellucid than. thofe on the fialk; the(e furround the bafe of the pedicle clofely, and, when removed, difcover a purple tube, into which it is inferted. The bafe of the pedicle is no thicker than the refl:, but it is green ; the refi is of an orange colour. On the head of the pedicle there firfi appears a long, flender, and pointed pellicle, co-vering 7be Hiftory of P t A N T S. IOJ vering the embryo capfule; as this grows in magnitude, the calyptra appears more thick, and at length _fp.lits. The whole is made up of woolly fibres, without any membra?e; whe? this IS taken off, ~he capfules. are found to ~e fquare, large, and of a browmlb colour ; they. are filled With a greemih, or yellowtib powder. Among the plants which produce thefe capfules, there are others with their extremities, radiated i.n fo:m of a ftar. .B~erhaave firft fufpeeted thefe ftarry tops to be flowers; and Mtcheh adopted the opmton, from whom Linnreus has taken it to difiinguiib the genus by.; but all, that we fe~ prod;1ced from thefe ftarry tops, is no more than young plants like the former, growmg as It were out of the head of the old one. they ~re fo~etimes feen proliferous in this manner, to the third and fourth degree. , Th1s fpecies grows very abundantly in our woods, and on heaths. Moft of the botanical writers ha~e d~fcrib.ed it u~der th~ naf!le of Polytrichum aureum majus, and Mufcus aur.e~s capil~ans ~aJOr. Lmnreus, m his Flora Laponica, calls it, Polytrichum caule fimpltct. Mtcheh has been fo fond of the opinion of the ftarry tops being flowers, that he has figured them fomething more like flowers than nature makes them. In very favourable foils, this plant will grow to a vafi length. 2 . Polytrichum ramofum capjula rotunda. Branched Polytrichum, with roundijh heads. The fquarenefs o~ the capfule~ has been by fome made the great difiingui01ing charaCter of the Polytncha ; but thts fpecies is a perfeCt Polytrichum in it's external form as well as it's charaCters, yet it's capfule is round. It grows to two or three inches i~ height. It's roots are fi brous and tou~h; it's ftalk is rigid and firm; it has few leaves) often none toward tl~e. bott?m ; but m the upper part it is very thick fet with them. The ftalk g~ne rall~ dtvides mto three or four branches, at about half way of it's height; thefe are about an mch l?ng. '!'he leaves are oblong, narrow, hollowed, and pointed at the ends. The pedtcles an(e ft:om the fummits of thefe ~ranches, and arc very fiender, about three quarters of an mch long, and of a yellowtlh colour. They are often fomewhat cr?o~ed : on the. tops of thefe fiand capfules of a roundiili, or, more properly, of ~n elhptic figure, bemg more protuberant on one part than in the reft. The calyptra Is. of a yellow colour, fhort and thick, but pointed at the top, and jagged or lacerated as 1t were at the bottom. The capfules are green at firft, but afterwards brown, and at length almofi blacki01. It's leaves, when examined by the microfcope, . are found to be lightly ferrated. It grows very plentifully on the Alps, and is found 1n fom~ p~rts of England. !h~ mountains of Wales are faid, in fome places, to abound w1th 1t. I have met with It on Mendip-hills. 3· Polytrichum capfolis rotundis fif!ilibus. Tbe round-headed Po!Jtrichum, with jhort pedicles, This is a ~ery fin gular plant, and would, at .firfl: .fight, be taken for a Mofs of almoft any oth~r, kmd, rather .t~an a. Polytrichum. It grows to about an inch and half in h~Ight; Its fi:alks are divided mto feveral ramifications, and are all over thick befet Wlt~ lhort and broad leaves. They are ~roadefi at the bafe, and terminate in a point whtc~, bends dowt~ward, and are pelluctd, and of .a pale green colour. The tops of the ~~ anches ~re thtc~er than ~ny othe!· part, and their leaves are often difpofed in a fiellar form . 1 he pedlCles whtch fufiam the capfules are extreamly fl10rt, and do not grow fi·om the mtddle of thefe, but from the bafes of the other leaves, and alfo from th~ bafes of thofe on the ftal~s. The capfules are of an oval figure, and are covered wlth a calyptr~, fhor~ and pomted, and very hairy, the hairs ftanding ereCt, not lying dow~ lengthw1fe, as m moll: of the other fpecies. It IS common on the barks of old trees, at~d alfo ~n old walls; fometimes on pales, and the fides. of houfes. ~any of the botamcal wnters have defcriberl it, but few of them. have dtfcovercd. that It belonged to this genus. Ray calls it, M ufcus apocarpos ar~onbus adna(ce~s mmor. Tourne.f~rt, Mufcus capillaceus, minim us, acaulos, calyptra ftnat~ ; a~d ~onfo~, Mu~cus humtlts tectorum, fubfufcus, capitulis brevibus, pileolis ereCtts pedtcuhs cu ~tts. Vatllan.t has figured it, but not accurately. . The other fpectes of Po~ytnchu m .are, r. T.he Ieifer, fquare-headed, heath PoJytnc~ um. 2. The leafl: hatry Polytnchum, wlth fquare heads. 3• The branched, urn- |