X Y L 



X Y L 



/3ctr platanoides, and A. campejlre, in the autumn. It con- 

 fifts of numerous, black, opaque, infeparable patches, fcat- 

 tered over the upper fide of the leaf, each about a quarter 

 or one-third of an inch in diametLr ; the margin fonietimes 

 varioufly and elegantly notched, or fringed, and always cir- 

 cumfcribed by a very ftriking yellow, or tawny, difcolora- 

 tion of the leaf. Perfoon fays he has obferved the furface 

 of this fpecles, though ufually almoll even and uniform, 

 cracking into waved bordered iiffures. We can fee fome- 

 thing of this in a fpecimen from profeflor Schrader. 



4. X. putidatum. Sycamore Xyloma. Perf. n. 4. Obf. 

 Mycol. V. 2. 100. — Dilated, thin, imperfeftly orbicular, 

 fomewhat convex, black. Receptacles unequal, aggregate, 

 parallel, oblong, blunt, fuperficial. — Frequent on the fading 

 or fallen leaves of Acer Pfeudoplatanus, which are rarely 

 without this parafite in autumn and winter. The patches 

 are from half an inch to an inch wide, clofely united with 

 the leaf, (lightly convex above, and rather concave at the 

 under iide, which is fomewhat blackened by them, efpecially 

 at the circumference of each. The wrinkles, or receptacles, 

 are fhaped like the clefts of an Opegrapha (fee that arti- 

 cle) ; but much more (hallow, as well as more uniform in 

 colour. 



5. X.Jlellare. Starry Xyloma. Perf. n. 5. Obf. My- 

 col. v. 2. 100 " Thin, pitchy ; the margin fringed with 



radiating fibres." — Found by Perfoon, on the leaves of Phy- 

 teuma fp'icatum, though rarely. About half an inch broad, 

 more or iefs, of a handfome appearance, with an uniform 

 fmooth diHc, very black ; the marginal fringe either 

 black, or greyifh. No diftinft receptacles have yet been 

 noticed. 



6. Y^.\ rulrum. Red Xyloma. Perf. n. 6. Obf. Mycol. 

 V. 2. loi. — " Aggregate, orbicular, fomewhat confluent, 

 red." — Generally found in autumn on the leaves of Prunus 

 domejllca, rarely on P.fpinofa. At firil light the red colour of 

 this fpecies, all the others being black, caufes it to be taken 

 for an CEcidium, or Uredo ; but on examination the internal 

 fubftance proves to be folid, uniform, fcarcely containing 

 dillinft receptacles, or fced--vej[els ; its genus, however, is 

 reckoned by Mr. Perfoon as very doubtful. The patches 

 are each from two to four lines broad, rather thick, with 

 darker-coloured fuperficial dots, vifible only with a micro- 

 fcope. Perfoon. 



Seft. 2. Simple. Receptacles folitary, Jcattered ; generally 

 rounded, like a Peziza ; or dot-liLe. Smaller. 



7. li.. pezizcides. Cup-like Xyloma. Perf. n. 7. (Pe- 

 7.iza comitialis ; Sowerb. Fung. t. 118. P. viridis ; Bolt. 

 Fung. t. 109. f. I.) — Rather crowded, orbicular, black ; 

 opening at length, with an upright, fomewhat crenate, 

 ■ border, and a pale olive or greeni(h diflc. — Found on fallen 

 leaves of oak in December ; more rarely, and in Iefs per- 

 feftion, on thofe of beech. The fpecimcns are pretty uni- 

 form in (ize, larger than mullard-feed, clofely attached to the 

 furface of the leaf ; the border of each fometimes pale, 

 fometimes black, unlefs Sowerby and Bolton defcribe two 

 different fpecies. 



8. X. fpharioldes. Dot-hke Xyloma. Perf. n. 8. — 

 " Scattered, dot-hke, foftiih, with an open diflc, and a col- 

 lapfed inflpxed border." — On the leaves of Salix caprea. 

 This at a dillance refembles Sphsria punffiformis ; but under 

 a magnifier it looks like fome Pezma, with a crifped mar- 

 gin. The outfide is black ; the diflc, rarely all difplayed, 

 is paler. 



9. X. hyjlerio'ides. Oblong Xyloma. Perf. n. 9. " Ic. 

 tt Defer. Fung. t. 10. f. 3, 4." — " Elliptical, (hining, ranged 

 ntarly parallel.'' — On the fallen leaves of Hawthorn, in the 

 Spring. Each plant is one-third of a line long, ovate, or 



elliptical, of a (hining black ; folid within. A longitudinal 

 line feems to mark the place where it finally burfts. 



10. 'K.-falignum. Willow Xyloma. Perf. n. 10. ("Sphae- 

 ria fahgna ; Ehrh. Crypt, n. 299.") — "Aggregate and 

 rather crowded, orbicuLir, thin, with a fomewhat convex 

 diflv." — On the leaves of Salix caprea, occupying nearly their 

 whole furface. Each individual is from one-third to one- 

 half a line broad. 



11. 'X.. popuUnum. Afpen Xyloma. Perf. n. 11. — "Ag- 

 gregate, flattened, varioufly (haped, fmooth, opaque, black." 

 — Found on the old leaves of Populus tremula, in the fpring. 

 About a line broad ; the diili here and there grevilh. 



12. X. concentricum. Concentric Xyloma. Perf. n. 12. 



Obf. Mycol. V. 2. loi " Simple. Receptacles fmall, 



orbicular, depreffed, fomewhat conical, concentrical, of a 

 footy grey." — On half-decayed leaves of Populus tremula, 

 forming circular patches, near an inch broad. Receptacles 

 like Imall Icattered dots, at firft black, afterwards footy or 

 greyifli, burfting finally at the fummit. 



13. 'K. fagineum. Beech Xyloma. Perf. n. 13. " Difp. 

 Meth. Fung. 52." — " Minute, crowded, of a (hining black, 

 orbicular, plaited, a little depreffed." — Found on the under 

 fide of fallen and dried leaves of Beech, in the form of 

 crowded black dots. 



14. X. alneum. Alder Xyloma. Perf. n. 14. — " Mi- 

 nute, fcattered, roundilh, plaited." — This fpecies is met 

 with in fummer, upon Alder-leaves, while they are ftill 

 green. It confifts of a few black diftant dots. 



Thefe minute prodnftions are neceffarily very obfcure in 

 their charafters and economy. The prefent genus is marked 

 by Its internal folidity, of a corky or woody fubftance, 

 having nothing of a gelatinous nature, nor are there any dif- 

 tindl round capfular receptacles, as in Spkteria. See that 

 article. 



XYLOMELUM, fo called by the writer of this, from 

 |uAov, luood, and y-uAcv, an apple, in alliifion to the hardnefs 

 and form of the fruit, which procured it, wlien firft difco- 

 vered, the appellation of the wooden pear. — Sm. Tr. of 

 Linn. Soc. v. 4. 214. Mart. Mill. Di(5l. v. 4. Brown 

 Prodr. Nov. HoU. v. I. 387. Tr. of Linn. Soc. v. 10. 189. 

 212. — Clafs and order, Tetrandria 

 Proieaceee, Julf. Brown. 



Cor. Petals four, regular, equal, 

 linear ; externally hairy ; a little dilated and concave at the 

 tip ; revolute foon after expanfion. Neiitary four glands at 

 the bafe of the germen. Stam. Filaments four, very (hort, 

 inferted rather above the middle of eacli petal, and becoming 

 prominent by its recurvation ; anthers linear, inflexed, of 

 two lateral parallel lobes, with a membranous edge ; im- 

 perfeft in fome of the flowers. Pijl. Germen fuperior, 

 roundifl:) ; ftylc ereft, rigid, the length of the petals, deci- 

 duous ; ftigma vertical, club-(haped, obtufe, often fmall and 

 abortive. Peric. Folhcle woody, very thick, ovate, of one 

 excentric fmall cell, and burfting into two divaricated half 

 valves, at the point. Seeds two, roundifh, compreffed, each 

 with a terminal, oblong, rather oblique, membranous wing, 

 as long as the follicle. 



Eff. Ch. Petals four, bearing the petals above the middle, 

 regular, revolute. Neftariferons glands four. Stigma club- 

 (haped. Style deciduous. Follicle woody, of one excentric 

 cell, with two winged feeds. 



\. "K. pyriforme. Wooden-pear. Brown n. i. (Bankfia 

 pyriformis; Gsertn. v. I. 220. t. 47. f. I. iamarck lUuftr. 

 V.' I. 242. t. 54. f. 4. White's Voyage 224. t. 21. Hakea 

 pyriformis ; Cavan. Ic. v. 6. 25. t. 536. )— Gathered on the 

 eaftern coaft of New Holland, near Port Jackfon, by the 

 firft fettlers in that colony. We received fpecimens from 



Dr. White, 



Ait. Hort. Kew. v. I. 



Monogynla. Nat. Ord. 



Gen. Ch. Cal. none. 



