sides. Spermogonia immersed, conical, honey-coloured. Pseudoperidia white, opening irregularly. Spores elliptical or polygonal, coarsely verrucose, 16-30 X 15-17μ. Synonyms. Ecidium elatinum. Alb. and Schw., "Consp.," p. 121. Peridermium elatinum, Alb. and Schw. Cooke. Seem. Jour. Bot., vol. ii. p. 34; “Hdbk.,” p. 535; "Micro. Fungi,” 4th edit., p. 194. On Pinus picea. Ecidium pseudo-columnare. J. Kühn. Pseudoperidia in two rows on the under side of the affected leaves, which are not altered in length or breadth, but are paler than the healthy ones. Pseudoperidia spherical, ovate, or elongate, 5-2 mm. high, edges irregularly torn. Spores white, finely verrucose, ovate, elongate elliptical, or irregular, often triangular in section, 33-37 × 18-25μ. Synonyms. J. Kühn, "Hedwigia," 1884, p. 168. Peridermium columnare, Alb. and Schw. Cooke, "Hdbk.," p. 535; "Micro. Fungi," 4th edit., p. 194, t. ii. figs. 27, 28. Exsiccati. Cooke, i. 214. Vize, "Micro. Fungi Brit.," 60. On Abies pectinata, nordmaniana, amabilis, cephalonica. BIOLOGY.-Æcidium columnare was found by De Bary to be the Æcidium of Melampsora goeppertiana, Kühn; but the teleutospores have not up to the present time been found in England, although their host-plant, Vaccinium vitis-idæa, is by no means rare. I therefore submitted specimens of this species to Professor Kühn, who found them to be his Ec. pseudo-columnare, the life-history of which is distinct from Ec. columnare. DESCRIPTIONS OF THE BRITISH USTILAGINEÆ. USTILAGINEÆ. Schröter. FUNGI parasitic in the tissues of living plants. Mycelium widely spreading, but soon vanishing. Teleutospores produced in the interior of mycelial branches, which often become gelatinized. Germination of the spores by a promycelium and promycelial spores (sporidia), or by continuous sprouting, after the manner of yeast-spores. Ustilago. Pers. Teleutospores simple, produced in the interior of much gelatinized swollen hypha; when mature forming pulverulent masses. Germination by a septate promycelium, which produces promycelial spores (sporidia) both laterally and apically, but principally the former. *Teleutospores smooth or obscurely punctate. Ustilago longissima. (Sow.) Forming long parallel lines, mostly on the upper side of the leaves, soon pulverulent, olive-brown. Teleutospores globose, sometimes discoid, often irregular, pale olive-brown, smooth, 3'5-4μ in diameter, 6-7μ long. Promycelia very short. Synonyms. Ustilago longissima. Winter in Rabh., "Krypt. Flor.," vol. i. Ustilago longissima, Tul. Cooke, " Hdbk.," p. 512; "Micro. Fungi," 4th edit., p. 229, t. v. figs. 105-107. Uredo longissima. Sow., t. 139. Berk., "Eng. Flor.," vol. v. pt. ii. p. 375. Exsiccati. Baxter, 230. Cooke, i. Vize, "Fungi Brit.," 33. On Glyceria aquatica and fluitans. Throughout the summer and autumn. BIOLOGY.-The affected plants seldom if ever develop their inflorescence. Intermixed with the teleutospores are a number of pale cells, the function of which is unknown. For an account of the germination of the teleutospores, see p. 81. Ustilago hypodytes. (Schlecht.) Produced on the culms, beneath the leaf-sheaths, soon exposed, black, with a tinge of olive, pulverulent. Teleutospores subglobose, oblong, or angular, pale yellowish brown, subtransparent, smooth, 3-6 × 3-4'5μ, mixed with others much larger. Synonyms. Caoma hypodytes. Schlecht., "Flor. Berol.," vol. ii. p. 129. Ustilago hypodytes, Fries. Winter, loc. cit., p. 87. Cooke, "Hdbk.," p. 513; "Micro. Fungi," 4th edit., p. 229, t. v. figs. 100, 101. Exsiccati. Cooke, i. 56; ii. 433. Vize, "Fungi Brit.," 35. On Triticum repens, junceum, Elymus arenarius, Bromus erectus, Psamma arenaria. June to November. BIOLOGY.-See p. 80. Ustilago segetum. (Bull.) Produced in the receptacle and rachis, destroying the whole inflorescence, dusty, black, with an olive-brown lustre. Teleutospores globose or irregular, often flattened on one side, pale T yellowish-brown, subtransparent, smooth or obscurely punctate or granular, 5-8μ in diameter. Synonyms. Reticularia segetum. Bull., "Champ.," vol. i. p. 90, t. 472, fig. 2. With., vol. iv. p. 356. Johnst., "Flor. Berw.," vol. ii. P. 442. Purton, vols. ii., iii. No. 1079. p. 203. Grev., "Flor. Edin.," Uredo segetum. Pers., "Disp. Meth.," p. 56. Berk., "Eng. Flor.," vol. v. p. 314. Ustilago carbo, Tul. Cooke, "Hdbk.," p. 512. Ustilago segetum (Bull.). Winter, loc. cit., p. 90. Cooke, "Micro. Fungi," 4th edit., p. 229, t. v. figs. 98, 99. Exsiccati. Cooke, i. 54; ii. 428, 430, 432. Baxter, 43. Vize, "Fungi Brit.," 31. On Avena elatior, sativa, Triticum vulgare, Hordeum vulgare, distichum, hexactichum. May and June. BIOLOGY.-See p. 74, and p. 101. Mr. J. L. Jensen, of Copenhagen, has recently published his observations on the biology of this species. He has succeeded in infecting oats, barley, and wheat, by removing the external envelopes of the seeds and applying the spores to the bare kernels. He finds that the varieties of U. segetum which occur upon the above plants are biologically distinct, the Ustilago from the one cereal being incapable of infecting the others. Upon barley he finds two well-marked forms, var. tecta and nuda. Of these nuda is by far the most common. The spores have a tinge of yellow when seen en masse; they are rather smaller than those of tecta. The affected ears are completely destroyed, excepting the rachis, and the spores soon scattered. Tecta, on the other hand, has somewhat larger spores, which, when seen en masse, are jet-black. The affected ears are nearly twice as broad as the healthy ones, and do not emerge from the top of the leaf-sheath, but burst through laterally. Each of the affected kernels retains its shape for a considerable time, being enclosed in a membranous investment. The spores escape through minute fissures which appear in this membrane. Tecta has been found in the island of Iona, but it doubtless occurs all over Britain. Ustilago grandis. Fries. On the caulms beneath the leaf-sheath, often occupying whole internodes, black, dusty. Teleutospores globose, elongated or irregular, pale brown, smooth, 7-12 × 6-8μ. Synonyms. Ustilago grandis. Fries, "Syst. Mycol.," vol. iii. p. 518. Schröt., "Krypt. Flor. Schl.," vol. iii. p. 268. Winter, loc. cit., 87. Ustilago typhoides. B. and Br., Ann. Nat. Hist., No. 480. Cooke, "Hdbk.," p. 513; "Micro. Fungi," 4th edit., p. 229, t. vi. figs. 128, 129. On Phragmites communis. July to November. BIOLOGY.-See p. 83. Ustilago grammica. B. and Br. Forming little transverse bands, consisting of short, parallel black lines, 2 mm. or more long. Teleutospores globose, very minute. Synonym. Ustilago grammica. B. and Br., Ann. Nat. Hist., No. 483. Cooke, "Hdbk.," p. 514; "Micro. Fungi," 4th edit., p. 229, t. vi. figs. 120, 121. On Aira cæspitosa and Glyceria aquatica. I have never met with this species; and am unable to give any details concerning its spore-germination. Ustilago marina. Durieu. Spore-masses blackish brown, forming swellings on the roots. Teleutospores of two forms: (a) globose or obtusely ovoid or elongated, 10-13μ; (b) irregularly ovoid elongate, 16 x 10-13μ, olive-brown, smooth. Synonym. F. v. Waldh., "Syst. des Ust.," p. 17. Ustilago marina. Cooke, "Grevillea," vol. xiv. p. 90. On Scirpus parvulus. |