LICHENS. 



[ 392 ] 



LICHENS. 



The Lichens are ordinarily divided into 

 two orders according to the structure of 

 their sporanges, which are either closed at 

 first, bursting subsequently by a pore or an 

 irregular orifice, containing the thecce as a 

 nucleus in the interior; or they are open from 

 an early period, and bear the thecce on the 

 upper, mostly concave surface (disk). 



GYM NOCARPI. One of the two orders of 

 Lichens, characterized by bearing open apo- 

 thecia, in the form of shields (scutella), cups 

 (scyphi), rings (annuli), or irregular cracks or 

 lines (lirellfB), with raised borders, &c. These 

 apothecia are either sessile on a flat, spreading 

 thallus, or raised on more or less developed 

 stalk-like processes of the branched and 

 shrubby forms. The upper open, often con- 

 cave surface of the apothecia, called the disk, 

 is clothed with thecse and paraphyses. 



ANGIOCARPI. One of the two orders into 

 which Lichens are divided, characterized by 

 the closed apothecia, where the thecae and 

 paraphyses are collected into a nucleus 

 enclosed in a case called the perithecium, 

 bursting at the summit by a pore or an irre- 

 gular opening to discharge the spores. The 

 apothecium is more or less globular, and 

 either imbedded in the thallus, or distinct 

 and raised above it. The perithecium either 

 entirely encloses the nucleus or is hemisphe- 

 rical, clothing the upper, projecting portion. 



Synopsis of the Families. 



A. Gymnocarpi. Apothecia open, thala- 

 mium expanded. 



* Thallus crustaceous. 



1 . Apothecia sessile, shield- 

 shaped, or rarely pel- 

 tate, disk somewhat 

 waxy, with a border 



formed by the thallus. . PARMELIACE^E. 



2. Apothecia free, circular, 



soon convex, with an in- 

 distinct margin. Disk 

 always open, in a spe- 

 cial excipulum LECIDINE^E. 



3. Apothecium oblong, li- 



near or waved, chan- 

 neled. Disk at first 

 connivent or with a veil . GR A p H I D E M . 



4. Apothecia circular or 



g'obose, always open, 

 isk pulverulent .... CALICHES. 



** Thallus gelatinous when fresh. 



5. Apothecia circular, thal- 

 lus composed of cylin- 

 drical and moniliform 



filaments COLLEMACE^E. 



. 



B. Angiocarpi. Apothecia closed, open- 

 ing by a terminal pore and bursting 

 irregularly, thalamium subglobose, 

 included. 



* Thallus crustaceous. 



6. Thallus shrubby, apo- 



thecia at the ends of 



the branches SPH^ROPHOREJ?. 



7. Thallus horizontal, 

 leaf-like or encrust- 

 ing, apothecia im- 

 mersed ENDOCARPE^E. 



8. Thallus encrusting, 

 apothecia rounded, 

 projecting from the 



thallus VERRUCARIE^B. 



9. Thallus encrusting, 

 apothecia rounded, 

 with a carbonaceous 

 hypothecium, apo- 

 thecia bursting in 

 various ways,nucleus 



mostly waxy, hard. . LIMBORIE^E. 



** Thallus gelatinous or soft-cartilaginous. 



10. Apothecia terminal, 

 on lobes of the thal- 

 lus LICHINE^B. 



BIBL. L. R. Tulasne, Memoire pour servir 

 a Vhistoire organograpJiique et physiologique 

 des Lichens, Ann. des Sc. nat. 3 ser. xvii. 

 1-153 et seq. ; On the Reproduction of Li- 

 chens and Fungi, Ann. Nat. Hist. 2nd ser. vol. 

 viii. p. 114 (translated from Comptes Rendus, 

 March 1851) ; Korber, Grundriss der Kry- 

 ptogamen-kunde, Breslau, 1848, Sy sterna Li- 

 chenum, 1854-5 ; Fries, Lichenographia 

 europcea reformata, Lund. 1831 ; Schserer, 

 Enumeratio critica Lichenum europaorum, 

 Bern. 1850 ; Hedwig, Theoria generationis, 

 fyc. ; Acharius, Lichenographia universalis ; 

 Wallroth, Naturgeschichte der Flechten, 

 Frankfort.-u.-M. 1825; Meyer, DieEntwickl. 

 fyc. der Flechten (Nebenstunden meiner Be- 

 schdftigungen, ^c.),1828; Montagne, Aper$u 

 morphologique de la famille des Lichens, 

 Diet. univ. d'hist. nat. Paris, 1846 ; Bayr- 

 hoffer, Einig. ub. Lichen., Berne, 1851 ; It- 

 zigsohn, Botan. Zeit. viii. 393. 913. ix. 153; 

 Flotow, numerous papers in the 'Flora' and 

 Botanische Zeitung ; Leighton, British An- 

 giocarpous Lichens; Ray publications, 1851. 



LICHINA, Ag. A genus of Lichineae 

 (Lichens), allied to COLLEMA and EPHEBE 

 in many respects, formerly included among 

 the Alga? on account of their growing on the 

 sea-shore (near high-water mark) ; but 

 having the thallus of a lichen, and bearing 



