SPH^RIACEI. 



[ 585 ] 



SPHiERIACEI. 



sions, growing upon leaves, stems, bark, 

 wood, &c., and sometimes on the bodies of 

 insects. The essential distinctive character 

 lies in the globular, ovate, or jflask-shaped 

 conceptacle or perithecium, containing asci, 

 which ultimately open by a pore at its sum- 

 mit to discharge the spores. These peri- 

 thecia occur either solitary or in groups on 

 an indistinct matrix, growing out from the 

 epidermis of leaves, &c. (Sphceria), or they 

 are immersed in a tubercular stroma {Nec- 

 tria), while in the larger forms the stroma 

 becomes developed into an erect clavate or 

 bushy structure, of a fleshy or horny con- 

 sistence, the perithecia being imbedded in 

 the superficial layer of this, and opening by 

 pores on the surface. Much remains to be 

 done in reference to the history of this fa- 

 mily, not merely on account of the polymor- 

 phous characters of the ascophorous forms, 

 but from the circumstance that it has re- 

 cently been shown, as was suspected before, 

 that there is a relationship existing between 

 them and the supposed genera of Coniom} - 

 cetous Fungi of similar habit. These last 

 are in fact mostly forms of Sphaeriaceous 

 Fungi, as is indicated under the heads Co- 



NIOMYCETES, AsCOMYCETES, DoTHIDEA, 



Sph^ria, Cytispora, Septoria. Our 

 treatment of this family is very imperfect, 

 the knowledge of them being confined to 

 few persons, and much of it lying scattered 

 in fragments. 



Synopsis of British Genera. 

 * Stroma erect. 



I. Claviceps. Stroma simple, clavate ; 

 perithecia superficial, in a distinct layer at 

 the summit of the clavate stroma ; asci tu- 

 bular, spores very long, multiseptate. 



II. Xylaria. Stroma simple or branched, 

 perithecia spread all over, often wanting at 

 the summit, black ; asci eight-spored, spores 

 uniseptate. 



III. Thamnomyces. Stroma branched, 

 shrubby, or stalk-like ; perithecia formed 

 from the stroma, more or less naked ; asci 

 tubular; spores simple, ovate. 



** Stroma between erect and horizontal. 



IV. PoRONiA. Stroma cup-shaped, sti- 

 pitate or sessile, margined ; perithecia in the 

 disk, superficial j ostioles even slightly pro- 

 minent. 



*** Stroma horizontal. 



V. Hypocrea. Stroma distinct from the 



matrix, tubercular; perithecia immersed; 

 asci filiform ; spores simple or uniseptate. 



VI. Hypoxylon. Stroma distinct from 

 the matrix, at first covered with a floccose, 

 mealy veil; perithecia black; asci linear- 

 clavate; spores subseptate, expelled in a 

 cloud of black powder. 



VII. Diatrype. Stroma partly formed 

 from the matrix, not distinct; perithecia 

 deep-seated, produced into a long neck, and 

 frequently a beak ; spores simple and pel- 

 lucid. 



VIII. DoTHiDEA. Perithecia indistin- 

 guishable from the stroma; asci collected 

 into a globose nucleus with a neck above, 

 leading to an ostiolate papilla. 



**** Stroma wanting; the perithecia often 

 seated on a tubercidose, crustaceous, bys- 

 soid, macular mycelium. 



IX. Nectria. Perithecia free, membra- 

 nous, flaccid, brightly coloured, with a pale 

 papilla, nucleus pale ; asci eight-spored ; 

 spores pellucid. 



X. OoMYCEs. Perithecia erect, several 

 contained in a shining sac, free towards the 

 upper part; ostiole punctiform ; asci linear; 

 spore filiform, very long. 



XI. Sph^ria. Perithecia black, papilla 

 covered by a veil or by the matrix, some- 

 times beaked, indurated, ostiolate, black ; 

 asci usually eight-spored ; spores usually 

 septate, discharged as a powder. 



Fig. 655. 







m 



Fig. 656. 



Fig. Q^b^J. 



Xylaria guianensis. 



Fig. 655. A stroma. Nat. size. 



Fig. 656. Vertical section of the same. Nat. size. 



Fig. 657. Section of a perithecium. Magnified 10 dia- 

 meters. 



