Oidium.] FUNGI. 349 



3. 0. fructigenum, Sclim. {Fruit Oidium) ; tufts subconipact 

 at first villous with white branched flocci then with simple 

 cream-coloured flocci breaking up into oval pellucid joints. 

 Kuvze and Schm. Myc. Heft. 1. p. 80. t. 2. f, 22. Lk. Sp. 1. 

 p. 122. Fr. St/St. Myc, v. \.p. 430. DesmJ n. 512. — Torula 

 fructigena, Pers. Obs. Myc. 1. t. 1./. 7. 



On decayed pears, apples, plums, &c. exposed to wet. Apethorpe, 

 Norths. Rev. M. J. Berkeley. — There is a distinct hemispheric 

 black stroma, resembling a Sclerotiuni. Cream-coloured, greyish, or 

 tUwn-coIoured. 



4. O. monilioides, Lk. (nechlace Oidium) ; tufts loose white 

 or yellowish, flocci simple breaking up into oval joints. Lk. Sp. 

 \.p.\22. Fr. Syst. Myc. v. 3. p. 43 1 . — Acrosporivm monilioides, 

 Nees, f. 49. b. Johnst. FL Berw. 2. p. 211. — Monilia hyalina, 

 Fr. bhs. \.p. 210. t. S.f. 4.— Torida monilioides, Corda, I. c. t. 



34. — IS. joints globose Acrosporiiim monilioides, Grev. ! Scot. 



Crypt. FL t. 73. Fl. Ed. p. 469. 



On leaves and culms of grasses. Common. — Dr. Greville's plant 

 has the articulations perfectly globose, in specimens before me ; exactly 

 as represented in liis figure. Piiccinia minuta, Sow., growing on some 

 Asterophora, though quoted here by Fries, is surely different. 



5. O. erysiphoides, Fr. {Mildew Oidium) ; widely eff*used inde- 

 terminate white, fertile flocci collected here and there into little 

 heaps, entirely breaking up into oval-oblong joints. Fr. Syst. 

 Myc. V. 3. p. 430. — SporoiricJium macrosporum, Grev. Fl. Ed. 

 p. 464 Torula hotryoides, Corda, I. c. t. 35. 



On leaves of various plants, common. Very destructive to peach- 

 trees, cabbages, &c. In the former case its progress is sometimes 

 stopped by powdering the leaves and fruit with sulphur. 



6. O. leucoconium, Desm. {small mildew Oidium) ; white, form- 

 ing eft^ised spots, flocci distinct not jointed below, breaking up 

 into oval sporidia. Desm. e.vs. n. 303. Ann. d. Sc. Nat. v. 17. 

 t. 6. Fr. Syst. Myc. v. 3. ;;. 432 — Var. ulmaria, Desm. n. 511. 



On leaves of various plants, especially \\o=>cs.—Spor(>trichum 

 macrofiponim, Grev. ! belongs in part to this species, wiiich is perhaps 

 too closely allied to the foregoing, for in that 1 always find a short 

 inarticulate peduncle. I am i\iclined to think that lunger's Ci/lindrO' 

 sporium conantricum, in his work on the Exanthemata of plants, is 

 only a state of the present species. Fari/iaria sctuiiiaria. Sow., appears 

 to nic to be a small imperfect Credo accompanied by a gununy exusion 

 from the leaves intermixed with either tiiis or the foregoing species. 



7. O. fascicuhitum, Berk, {fascicidati Oidium) ; filaments 

 branched somewhat fasciculate erect forming spreading tufts 

 white at first, at length of a fine glaucous hue. — Acrosporium 



fasciculalum, Grev. Fl. Ed. p. 4G9. 



On putrefying oranges. J)r. Grcville.—'' Commencing at first in 

 minute, distiiict, pulverulent spots, whitii speedily become confluent 

 and deep glaucous." Grev. I. c. 



