exciple

_Lecideaceae_, the line of evolution seems to have been in the direction of a well-developed exciple and from simpler to more complex spores.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Thallus granulose, verrucose, or areolate, rather better developed than those of the preceding genera as shown in the more frequent verrucose and areolate conditions; apothecia minute to large, sessile to immersed, the disk and the exciple usually black; hypothecium usually brown; hymenium pale to light brown; paraphyses usually distinct; spores brown,

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Thallus of very minute inconspicuous and evanescent, brown-black granules; apothecia minute, 0.2 to 0.4 mm. in diameter, adnate, dark brown to black, scattered or clustered, plain with a thin concolorous exciple visible, to convex with the exciple finally covered; hypothecium dark brown; hymenium pale brown; asci clavate; paraphyses coherent-indistinct; spores oblong-ellipsoid, 9 to 15 mic. long and 5 to

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Thallus commonly granulose, and often passing into verrucose and chinky conditions, but scarcely ever areolate, sometimes scant and evanescent; apothecia usually minute or small, and commonly adnate, exciple weak and often becoming covered; hypothecium and hymenium passing from pale through shades of brown, the former becoming darker than the latter, this rarely tinged blue or violet above; spores hyaline, 2-celled.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

A vertical section through an apothecium of _Lecidea rupestris_: a, the hymenium, composed of asci and paraphyses; b, the hypothecium; c, the mycelium, the cells of the algal host, and particles of the limestone on which the plant was growing; d, the weak, light-colored, covered exciple.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

A small portion of a section through the exciple of _Peltigera canina_, showing the plectenchymatous structure.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Thallus granulose to verrucose and subareolate, sometimes inconspicuous and evanescent; apothecia minute to middle-sized, adnate or more or less immersed, exciple usually prominent and persistent, but sometimes becoming covered, disk flat to convex; hypothecium and hymenium pale to brown; spores simple, hyaline, minute, numerous in each ascus.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Thallus usually composed of minute granules, these often run together to form a leprose or verrucose and rarely areolate or even subsquamulose crust, rarely disappearing; apothecia minute or small, usually adnate, with a weak and often covered exciple; hypothecium pale to dark brown; hymenium pale or tinged brown; spores hyaline, usually fusiform or dactyloid, varying from 4 - to 9-celled.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Thallus light colored, usually thin and smooth, rarely disappearing; apothecia minute to middle-sized, 0.2 to 1 mm. in diameter, adnate scattered or crowded, flat or slightly convex, the disk pruinose, and the exciple persistent; hypothecium lighter or darker brown; hymenium usually pale; paraphyses coherent and becoming indistinct; asci cylindrico-clavate; spores oblong-ellipsoid, 3 to 5 mic. long and 1 to

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894

Rarely the thallus extends upward as a veil which surrounds the apothecia laterally and suggests how the thalloid exciple of higher families probably arose.

Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 The Ascomycetes of Ohio IV and V Leafy Jane Corrington Hilker 1894