Acrogenous, borne at the tips of hyphae; see spermatium, 312.

Allelositismus, Norman’s term to describe the thallus of Moriolaceae (mutualism), 313.

Amorphous cortex, formed of indistinct hyphae with thickened walls; cf. decomposed cortex.

Amphithecium, thalline margin of the apothecium, 157.

Antagonistic symbiosis, hurtful parasitism of one lichen on another, 261 et seq.

Apothecium, open or disc-shaped fructification, 11, 156 et passim. Veiled apothecium, 169. Closed or open at first, 182.

Archilichens, lichens in which the gonidia are bright green (Chlorophyceae), 52, 55 et passim.

Ardella, the small spot-like apothecium of Arthoniaceae, 158.

Areola (areolate), small space marked out by lines or chinks on the surface of the thallus, 73 et passim.

Arthrosterigma, septate tissue-like sterigma (spermatiophore), 197.

Ascogonium, the cell or cells that produce ascogenous hyphae, 180 et seq.

Ascolichens, lichens in which the fungus is an Ascomycete, 159, 173 et passim.

Ascus, enlarged cell in which a definite number of spores (usually 8) are developed; cf. theca, 157, 184.

Ascyphous, podetia without scyphi, 119 et passim.

Biatorine, apothecia that are soft or waxy, and often brightly coloured, as in Biatora, 158.

Blasteniospore, see polarilocular spore.

Byssoid, slender, thread-like, as in the old genus Byssus.

Campylidium, supposed new type of fructification in lichens, 191.

Capitulum, the globose apical apothecium of Coniocarpineae; cf. mazaedium, 319.

Carpogonium, primordial stage of fructification, 160, 164 et passim.

Cephalodium, irregular outgrowth from the thallus enclosing mostly blue-green algae; or intruded packet of algae within the thallus, 11, 133 et passim.

Chrondroid, hard and tough like cartilage, a term applied to strengthening strands of hyphae, 104, 114.

Chroolepoid, like the genus Chroolepis (Trentepohlia).

Chrysogonidia, yellow algal cells (Trentepohlia).

Cilium, hair-like outgrowth from surface or margin of thallus, or margin of apothecium, 91.

Consortium (consortism), mutual association of fungus and alga (Reinke); also termed “mutualism,” 31, 313.

Corticolous, living on the bark of trees, 363.

Crustaceous, crust-like closely adhering thallus, 70-79.

Cyphella, minute cup-like depression on the under surface of the thallus (Sticta, etc.), 11, 126.

Decomposed, term applied to cortex formed of gelatinous indistinct hyphae (amorphous), 73-81 et passim, 357.

Determinate, thallus with a definite outline, 72.

Dimidiate, term applied to the perithecium, when the outer wall covers only the upper portion, 159.

Discoid, disc-like, an open rounded apothecium, 156.

Discolichens, in which the fructification is an apothecium, 160 et seq.

Dual hypothesis, the theory of two organisms present in the lichen thallus, 27 et seq.

Effigurate, having a distinct form or figure; cf. placodioid, 80, 201.

Endobasidial, Steiner’s term for sporophore with a secondary sporiferous branch, 200.

Endogenous, produced internally, as spores in an ascus, 179; see also under thallus.

Endolithic, embedded in the rock, 75.

Endosaprophytism, term used by Elenkin for destruction of the algal contents by enzymes of the fungus, 36.

Entire, term applied to the perithecium when completely surrounded by an outer wall, 159.

Epilithic, growing on the rock surface, 70.

Epiphloeodal, thallus growing on the surface of the bark, 77.

Epiphyllous, growing on leaves, 363.

Epithecium, upper layer of thecium (hymenium), 158.

Erratic lichens, unattached and drifting, 259.

Exobasidial, Steiner’s term for sporophore without a secondary sporiferous branch, 200.

Exogenous, produced externally, as spores on tips of hyphae; see also under thallus.

Fastigiate cortex, formed of clustered parallel hyphal branches vertical to long axis of thallus, 82.

Fat-cells, specialized hyphal cells containing fat or oil, 75, 215 et passim.

Fibrous cortex, formed of hyphae parallel with long axis of thallus, 82.

Filamentous, slender thallus with radiate structure, 101 et seq.

Foliose, lichens with a leafy form and stratose in structure, 82-97.

Foveolae, Foveolate, pitted, 373.

Fruticose, upright or pendulous thallus, with radiate structure, 101 et seq.

Fulcrum, term used by Steiner for sporophore, 200.

Gloeolichens, lichens in which the gonidia are Gloeocapsa or Chroococcus, 284, 373, 389.

Gonidium, the algal constituent of the lichen thallus, 20-45 et passim.

Gonimium, blue-green algal cell (Myxophyceae), constituent of the lichen thallus, 52.

Goniocysts, nests of gonidia in Moriolaceae, 313.

Gyrose, curved backward and forward, furrowed fruit of Gyrophora, 184.

Hapteron, aerial organ of attachment, 94, 122.

Haustorium, outgrowth or branch of a hypha serving as an organ of suction, 32.

Helotism, state of servitude, term used to denote the relation of alga to fungus in lichen organization, 38, 40.

Heteromerous, fungal and algal constituents of the thallus in definite strata, 13, 68, 305 et passim.

Hold-fast, rooting organ of thallus, 109, 122 et passim.

Homobium, interdependent association of fungus and alga, 31.

Homoiomerous, fungal and algal constituents more or less mixed in the thallus, 13, 68, 305 et passim.

Hymenial gonidia, algal cells in the hymenium, 30, 314, 315, 327.

Hymenium, apothecial tissue consisting of asci and paraphyses; cf. thecium, 157.

Hymenolichens, lichens of which the fungal constituent is a Hymenomycete, 152-154, 342.

Hypophloeodal, thallus growing within the bark, 78, 364.

Hypothallus, first growth of hyphae (proto- or pro-thallus) persisting as hyphal growth at base or margin of the thallus, 70, 257 et passim.

Hypothecium, layer below the thecium (hymenium), 157.

Intricate cortex, composed of hyphae densely interwoven but not coalescent, 83.

Isidium, coral-like outgrowth on the lichen thallus, 149-151.

Lecanorine, apothecium with a thalline margin as in Lecanora, 158.

Lecideine, apothecium usually dark-coloured or carbonaceous and without a thalline margin, 158.

Leprose, mealy or scurfy, like the old form genera, Lepra, Lepraria, 191.

Lichen-acids, organic acids peculiar to lichens, 221 et seq.

Lignicolous, living on wood or trees, 366.

Lirella, long narrow apothecium of Graphideae, 158.

Mazaedium, fructification of Coniocarpineae, the spores lying as a powdery mass in the capitulum, 176.

Medulla, the loose hyphal layer in the interior of the thallus, 88 et passim.

Meristematic, term applied by Wainio to growing hyphae, 48.

Microgonidia, term applied by Minks to minute greenish bodies in lichen hyphae, 26.

Multi-septate, term applied to spores with numerous transverse septa, 316 et seq.

Murali-divided, Muriform, term applied to spores divided like the masonry of a wall, 187.

Oidium, reproductive cell formed by the breaking up of the hyphae, 189.

Oil-cell, hyphal cell containing fat globules, 215.

Orculiform, see polarilocular.

Orthidium, supposed new type of fructification in lichens, 192.

Palisade-cells, the terminal cells of the hyphae forming the fastigiate cortex, 82, 83.

Panniform, having a felted or matted appearance, 260.

Paraphysis, sterile filament in the hymenium, 157.

Parasymbiosis, associated harmless but not mutually useful growth of two organisms, 263.

Parathecium, hyphal layer round the apothecium, 157.

Peltate, term applied to orbicular and horizontal apothecia in the form of a shield, 336.

Perithecium, roundish fructification usually with an apical opening (ostiole) containing ascospores, 158 et passim.

Pervious, referring to scyphi with an opening at the base (Perviae), 118.

Phycolichens, lichens in which the gonidia are blue-green (Myxophyceae), 52 et passim.

Placodioid, thallus with a squamulose determinate outline, generally orbicular; cf. effigurate, 80.

Placodiomorph, see polarilocular.

Plectenchyma (Plectenchymatous), pseudoparenchyma of fungi and lichens, 66 et passim.

Pleurogenous, borne laterally on hyphal cells; see spermatium, 312.

Pluri-septate, term applied to spores with several transverse septa, 321 et seq.

Podetium, stalk-like secondary thallus of Cladoniaceae, 114, 293 et seq.

Polarilocular, Polaribilocular, two-celled spores with thick median wall traversed by a connecting tube, 188, 340-341.

Polytomous, arising of several branches of the podetium from one level, 118.

Proper margin, the hyphal margin surrounding the apothecium, 157.

Prothallus, Protothallus, first stages of hyphal growth; cf. hypothallus, 71.

Pycnidiospores, stylospores borne in pycnidia, 198 et passim.

Pycnidium, roundish fructification, usually with an opening at the apex, containing sporophores and stylospores; cf. spermogonium, 192 et seq.

Pyrenolichens, in which the fructification is a closed perithecium, 173 et passim.

Radiate thallus, the tissues radiate from a centre, 98 et seq.

Rhagadiose, deeply chinked, 74; cf. rimose.

Rhizina, attaching “rootlet,” 92-94.

Rimose, Rimulose, cleft or chinked into areolae, 73.

Rimose-diffract, widely cracked or chinked, 74.

Scutellate, shaped like a platter, 156.

Scyphus, cup-like dilatation of the podetium, 111, 117.

Signature, a term in ancient medicine to signify the resemblance of a plant to any part of the human body, 406, 409.

Soralium, group of soredia surrounded by a definite margin, 144.

Soredium, minute separable particle arising from the gonidial tissue of the thallus, and consisting of algae and hyphae, 141.

Spermatium, spore-like body borne in the spermogonium, regarded as a non-motile male cell or as a pycnidiospore, 201.

Spermogonium, roundish closed receptacle containing spermatia, 192.

Sphaeroid-cell, swollen hyphal cell, containing fat globules, 215.

Squamule, a small thalline lobe or scale, 74 et passim.

Sterigma, Nylander’s term for the spermatiophore, 197.

Stratose thallus, where the tissues are in horizontal layers, 70.

Stratum, a layer of tissue in the thallus, 70.

Symbiont, one of two dissimilar organisms living together, 32.

Symbiosis, a living together of dissimilar organisms, also termed commensalism, 31, 32 et seq.

Tegulicolous, living on tiles, 369.

Terebrator, boring apparatus, term used by Lindau for the lichen “trichogyne,” 179.

Thalline margin, an apothecial margin formed of and usually coloured like the thallus; cf. amphithecium.

Thallus, vegetative body or soma of the lichen plant, 11, 421. Endogenous thallus in which the alga predominates, 68. Exogenous thallus in which the fungus predominates, 69.

Theca, enlarged cell containing spores; cf. ascus.

Thecium, layer of tissue in the apothecium consisting of asci and paraphyses; cf. hymenium, 157.

Trichogyne, prolongation of the egg-cell in Florideae which acts as a receptive tube; septate hypha in lichens arising from the ascogonium, 160, 177-181, 273.

Woronin’s hypha, a coiled hypha occurring in the centre of the fruit primordium, 159, 163.