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expansions, or external to the original thallus, forming new individ. uals of the parent thallus ; and 2. by sporidia, consisting of subglobose or elliptical cells, which are either naked or contained in other elongated more or less vertical cells (asci), and immersed in the thalamium (or fructification proper), and propagate new individuals of the species. The thalamium is either rounded, gelatinouswaxy, and the asci converging (nucleiform); or flattened at length into a rigid, persistent, or afterwards collapsing lamina (subdisciform); or originally disciform (open); and is itself contained in a receptacle (exciple), either of the same color with and like the thallus (thalline exciple), or of different color and nature (proper exciple). The whole fructification constitutes the apothecium, which is typically round, though also occurring normally oblong and linear (lirelleform), and is either excavated with a contracted margin (urceolate); or slightly concave with an elevated margin (scutelliform); or very concave-scutelliform (cyathiform); or very concave-scutelliform and pervious (infundibuliform, a term applied also to the pervious cup-bearing podetia of Cladoniæ); or goblet-shaped and stipitate (crateriform); or dilated, fat, and without prominent margin (pellæform, of which the reniform is a variation); or convex with repressed margin (cephaloid); or between scutelliform and peltæform (disciform); or between scutelli. form and cephaloid (tuberculate). When the thalline exciple is prolonged below into a footstalk, it is said to be pedicellate; a proper exciple in like manner prolonged is said to be stipitale. When the proper exciple is originally and typically closed, the apothecium receives the name of perithecium. In the Angiocarpi several thalamia are sometimes contained in the same exciple (composile apothecia); and in the Gymnocarpi, in like manner, several disks are sometimes confluent (symphycarpeous apothecia). The colors of the thallus in Lichenes are disposed by Fries in four series : - 1. from pale green becoming glaucous ; 2. from yellowish green becoming ochroleucous ; 3. from dark green becoming fuscous or olivaceous ; 4. from pale yellow-green becoming lemon-colored. Each series has its peculiar variations. The glaucous runs into pale green, cerulescent, and white ; the fuscous into dark green, olivaceous, cinereous, grayishfuscous, and dark chestnut; the ochroleucous into yellowish green and albescent; the lemon-colored into pale yellow, orange-red, and vermilion-red.

SYNOPSIS OF The Genera.

Div. I. GYMNOCARPI, Schrader, Fries. Apothecia open, disciferous. 'Thalamium originally disciform, or becoming so, contained in a thalline exciple or a proper exciple ; disk normally persistent, ascigerous; sometimes originally pulveraceouscollapsed. Tribe I. PARMELIACEÆ, Fr. — Apothecia rounded, from con

cave becoming explanate, scutelliform, rarely peltate. Disk

somewhat waxy, persistent, contained in a thalline exciple. Subtribe 1. Usneez, Eschw. — Disk open. Thallus subvertical, or

pendulous-sarmentose, centripetal, without apparent hypothallus. 1. USNEA. Apothecia peltate ; thallus with a solid medullary layer. 2. EVERNIA. Apothecia scutelliform ; thallus fistulous, or with a

cottony medullary layer. 3. RAMALINA. Apothecia orbiculate-subpeltate ; disk pale, of nearly

the same color with the thallus. 4. CETRARIA. Apothecia scutellate-peltate, oblique. Subtribe 2. Parmelie E, Eschw. — Disk at first closed, becoming

at length discoid-open. Thallus horizontal, centrifugal, with a

hypothallus. 5. NEPAROMA. Apothecia reniform, adnate to the under side of the

lobes. 6. PELTIGERA. Apothecia peltæform, adnate to the upper side of

the elongated lobes. 7. SOLORINA. Apothecia maculæform, adnate to the disk of the

thallus. 8. Sticta. Apothecia scutelliform ; thallus with cyphellæ, or discol

ored spots, on the under side. 9. PARMELIA. Apothecia scutelliform ; thallus without veins or cy.

phellæ beneath. 10. ThelotreMA. Apothecia urceolate-scutelliform, a discrete inte

rior exciple veiling a rigescent disk. 11. GYALECTA. Apothecia urceolate, an elevated and discrete colored

margin bordering a nigrescent disk.

Tribe II. LECIDEACEÆ, Fr. Apothecia rounded, a persistent

tiam

disk contained in an open proper exciple, which it finally cov

ers, and becomes convex, cephaloid, and immarginate. 12. StereocauLWN. Apothecia turbinate, at length cephaloid ; pode

tia mostly solid. 13. CLADONIA. Apothecia at length cephaloid, inflated; podetia fistu

lous. 14. BÆomyces. Apothecia capitate, globose, immarginate, velate. 15. Blatora. Apothecia disciform, solid, with a waxy (originally

paler) exciple. 16. Lecidea. Apothecia disciform, solid, with a carbonaceous, black

proper exciple. Tribe III. GRAPHIDACEÆ, Fr. — Apothecia of various form,

an altered thalline carbonaceous proper exciple, or an originally proper exciple margining a gyrose and proliferous-papillate, or

canaliculate disk. 17. UMBILICARIA. Apothecia orbiculate or lirellæform ; thallus folia.

ceous. 18. OPEGRAPHA. Apothecia lirellæform ; thallus crustaceous. 19. LECANACTIS. Apothecia irregular, at first open, with a pruinose

thalline veil. Tribe IV. CALICIACEÆ, Fr. — Apothecia orbiculate or globose,

always open, margined by a proper exciple, the disk collapsing into naked sporidia ; or without an exciple, the sporidia ca

pituliform-compact. 20. TRACHYLIA. The carbonaceous exciple innate, with an asciger.

ous disk. 21. Calicium. The carbonaceous exciple free; disk compacted of

naked sporidia. 22. CONIOCYBE. Exciple wanting; sporidia capituliform-compact.

Div. II. ANGIOCARPI, Schrader, Fries.

Apothecia closed, nucleiferous, pertuse and with an ostiole, or irreg. ularly dehiscent; the nucleus included, subglobose, ascigerous. Tribe I. SPHÆROPHORACEÆ, Fr. — Apothecia formed of the

intumescent apices of the thallus, closed, at length irregularly lacerate-dehiscent. Nucleus subglobose. Thallus vertical, fruticulose.

23. SPHEROPHORON. Apothecia terminal, spherical; nucleus black,

dehiscent. Tribe II. ENDOCARPACEÆ, Fr. — Apothecia immersed in the

thallus, globose, the thalline exciple attenuated into a neck, and terminated by a discrete heterogeneous papillæform ostiole. Nucleus deliquescent. Thallus horizontal, foliaceous or crus

taceous. 24. ENDOCARPON. Apothecia pale, included in the foliaceous thallus. 25. Sagedia. Apothecia blackish, immersed in the crustaceous thallus. 26. PERTUSARIA. Apothecia verrucæform, with one or more blackish,

papillate ostioles. Tribe III. VERRUCARIACEÆ, Fr. — Apothecia rounded, a

closed proper exciple (perithecium) becoming pertuse with an ostiole, or at length open. Nucleus gelatinous, subhyaline, de

liquescent. Thallus crustaceous. 27. Conotrema. Perithecia at length open; nucleus subdisciform. 28. VERRUCARIA. Perithecia closed, with a papillæform or simply per

tuse ostiole. Tribe IV. LIMBORIACEÆ, Fr. — Apothecia rounded, the carbo

naceous proper exciple closed, at length variously dehiscent.

Nucleus subceraceous, rigescent. Thallus crustaceous. 29. PYRENOTHEA. Perithecia at length pertuse, protruding the fatiscent nucleus.

I. USNEA, Dill., Hoffm. Apothecia rounded, peltate, subterminal; disk open, placed upon the filamentous medullary stratum, the margin mostly radiate-ciliate. Thallus cartilagineous, at first erect, suffruticulose, becoming with age more or less filamentous or pendulous, the crustaceous cortical stratum somewhat separate from the medullary.

A genus universally diffused; and the first species occurring, in one or other of its forms, in every quarter of the globe. This species extends throughout the United States. U. homalea, Tuckerm. Enum. 1845, with a softish, much compressed, ancipital, rugulose, fastigiate and attenuate-branched thallus, and plane apothecia, with scarcely elevated, obtuse margins, Ramalina homalea, Ach. Lich. p. 598, was discovered on the coast of California by Menzies ! but has not been detected elsewhere.

1. U. barbata, Fr. Thallus terete, irregularly branched, at length annulate-cracked, glaucous ; apothecia almost immarginate, radiate, disk pale. Fr, Lichenogr. p. 18. — Q. florida, Fr., very much branched, somewhat scabrous, apoth. large. U. florida, Ach. B. strigosa, Ach., rather small, very thickly fibrillose-strigose. Ach. Syn. p. 305. — Y. rubiginea, Michx., lax, scabrous, more or less rusty-red. U. florida, var. rubiginea, Michz. Fl. 2, p. 332. — 0. hirta, very much branched, dwarfish, the fibrillæ somewhat elongated, oftener verrucose-pulveru. lent. U. hirta, Hoffm. 8. plicata, Fr., pendulous, elongated, subdichotomous, entangled, lax, smoothish, pale. U. plicata, Ach. — 5. da. sypoga, Fr., pendulous, elongated, branches somewhat simple, lateral fibres spreading. U. barbata, Hoffm. Lichen barbatus, L.

Very common; a, ß, , and & mostly on trees, the last two less frequently fertile; 8 on rails, sterile ; New England. New York, Torrey. Pennsylvania, Muhl. Northward to Arctic America, Richardson (Franklin's Narrative, App.).

2. U. longissima, Ach. Th. pendulous, filamentous, terete-compressed, somewhat rugulose, smoothish, nearly simple, pale glaucous, with approximate, horizontal, at length tortuous fibres. Ach. Syn. p. 307.

Firs and other trees on the sides, and in swamps at the base, of the high mountains of New England, and northward, occurring 5 feet long. Infertile, as is also the case with the European Lichen on which the species was founded. It seems, like the last species, to be very widely diffused; and I have, or have seen, specimens probably belonging to it, from Europe, Asia, Africa, and New Holland. A single Cape of Good Hope specimen, in my possession, is fertile, and has quite concave radiate apothecia, with sotnewhat elevated, obtuse margins. The earliest specimen I have seen is an infertile one in the Berlin herbarium, col. lected in Cappadocia by Tournefort.

3. U. anguluta, Ach. Th. pendulous, flexuous, angular, nearly simple, pale cinerascent; angles acute, scabrous ; fibres horizontal approximated, simple, short, terete-attenuate. Ach. Syn. p. 307. Halsey, Lich. New York, in Ann. Lyc. 1, p. 21.

Trees, Pennsylvania, Muhl., Ach. New York, Torrey. Massachusetts, occurring 4 feet long, Halsey. Spruce swamps, Chelmsford, Russell !

4. U. trichodea, Ach. Th. pendulous (prostrate), very delicate

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