Sect. II. Peridia in tufts or clusters.
Æcidium Berberidis, Pers. Berberry Cluster-Cups; spots roundish, bright red; subiculum thickened; peridia in subrotund or oval patches, often elongated; spores orange.—On leaves, peduncles, and fruit of the common Berberry. Common. May to July. (Plate I. figs. 7-9.)
Æcidium Thalictri, Grev. Meadow-Rue Cluster-Cups; collected in roundish clusters; peridia oblong; spores bright orange.—On Thalictrum alpinum. Not uncommon in Scotland.
Æcidium crassum, Pers. Buckthorn Cluster-Cups; spots yellow-brown, subiculum thickened; peridia crowded into a roundish heap, at first globose, yellow, at length open; spores orange.—On Rhamnus catharticus and R. frangula. Common.
Æcidium Periclymeni, DC. Honeysuckle Cluster-Cups; spots variegated, yellow and brown, subiculum thickened; peridia sometimes elongated, in roundish or effused heaps; spores orange.—On the under surface of Honeysuckle leaves. Not common. June to August.
Æcidium Calthæ. Grev. Marsh-Marigold Cluster-Cups; aggregate; peridia somewhat campanulate, with numerous minute marginal teeth; spores bright orange, subglobose or oval.—On leaves and petioles of Caltha palustris. Margin of peridia pale and brittle. Rare. Spring.
Æcidium Ranunculacearum, DC. Crowfoot Cluster-Cups; spots obliterated, subiculum thickened; peridia in irregular heaps, densely crowded together; spores orange.—On leaves of various Ranunculaceæ; very common on R. Ficaria, not uncommon on R. repens, more rarely on R. acris and R. bulbosus. Spring. (Plate II. figs. 12-14.)
Æcidium Galii, Pers. Bedstraw Cluster-Cups; spots linear or oblong, obscurely brown; peridia scattered, rarely aggregate, dentate, whitish; spores white.—On the leaves of Galium verum and G. mollugo. (Plate II. figs. 15-17.)
I am doubtful whether the Æcidium on Galium mollugo is really this species.—(M. C. C.)
Æcidium Bunii, DC. Pig-nut Cluster-Cups; spots obliterated, subiculum thickened; peridia in irregular subrotund or oval heaps; spores orange.—On Bunium bulbocastanum and Pimpinella saxifraga. Spring.
Æcidium Valerianacearum, Dub. Valerian Cluster-Cups; hypogenous, rarely cauline, spots on a thickened subcircular or oblong base; peridia scattered, more or less crowded, cup-shaped, tawny, margin erect, denticulate; spores dirty-yellow.—On Valeriana officinalis and V. dioica. North Britain.
Æcidium Asperifolii, Pers. Borage Cluster-Cups; clusters subrotund, on a slightly thickened subiculum; peridia scattered; spores yellowish-white.—On leaves of various Boragineæ. Summer. The parts of the leaves on which it occurs are rendered concave on one side and convex on the other.
Æcidium Grossulariæ, DC. Gooseberry Cluster-Cups; spots yellow, bright red on the opposite side, with a yellow border; peridia crowded in roundish heaps, at length brown, and surrounded with a brown area; spores orange.—On leaves and fruit of Gooseberry and Currant. Common. May to June.
Æcidium Urticæ, DC. Nettle Cluster-Cups; spots obliterated, subiculum thickened; peridia disposed in elongated or subrotund heaps, at first subglobose, then gaping; spores orange.—On leaves and stems of Nettles, distorting them very much. Common. June. (Plate I. figs. 10, 11.)
Æcidium Behenis, DC. Bladder-Campion Cluster-Cups; spots yellow, brown on opposite side; peridia somewhat circinating, in subrotund heaps; spores brown.—On Silene inflata. Not common. Some of the peridia are short and open, others larger and closed.
Æcidium Orobi, DC. Bitter-Vetch Cluster-Cups; spots yellow, effused; peridia scattered and disposed in small heaps; spores at length white.—On stems and leaves of Orobus tuberosus. Scotland.
Æcidium Compositarum, Mart. Composite Cluster-Cups; spots purplish, subrotund, confluent above; peridia crowded, in orbicular patches, or circinating, on the under surface; spores orange, oval.
Var. a. Taraxaci, Grev.; clusters small, scattered.—On leaves of the Dandelion. June to July.
Var. b. Prenanthis, Pers.; spots circular or irregular, purplish; subiculum incrassated.—On leaves of Hawkweed (Hieracium paludosum). Summer.
Var. c. Tussilaginis, Pers.; clusters round, on a thickened base; peridia circinating.—On the under surface of leaves of Coltsfoot and Butter-bur. Common. Autumn.
Var. d. Jacobæa, Grev.; pustular, soon becoming agglomerated, numerous, depressed; peridia splitting into short, brittle, yellowish-white teeth.—On leaves of Senecio Jacobæa and Sonchus arvensis. June to August.
Var. e. Lapsani, Purt.; spots purplish, irregular, confluent, on both sides of the leaves; peridia amphigenous, in irregular patches or scattered, not prominent, teeth numerous, minute, reflexed; spores yellow, oval.—On both surfaces of the leaves of Lapsana communis. April. Not uncommon.
Æcidium Saniculæ, Carm. Sanicle Cluster-Cups; spots purplish, slightly incrassated, small, scattered, roundish; peridia in small circulate clusters, hypogenous, and on the petioles, at first hemispherical, at length open, margin with from 4 to 6 spreading lobes; spores yellowish, elliptical.—On the under surface of the leaves and on the petioles of Sanicula Europæa. Not uncommon. May and June.
Æcidium Violæ, Schum. Violet Cluster-Cups; spots yellowish; peridia in irregular heaps, seriate and scattered; spores orange, at length brown.—On leaves, petioles, and sepals of Violets. Common. May and June.
Æcidium Poterii, Cooke. Burnet Cluster-Cups; spots obliterated, clusters subrotund or elongated; peridia hypogenous and on the petioles, circinating or scattered, immersed, margin irregularly fringed with numerous minute teeth, soon falling away; spores yellowish, oval.—On the under surface of the leaflets and on the petioles of Poterium Sanguisorba. Rare. May and June. Dartford Brent, Kent.
Æcidium Geranii, DC. Cranesbill Cluster-Cups; spots yellow and purple; peridia in circinating clusters; spores yellow, at length brown.—On the under surface of leaves of Geranium pratense and G. dissectum. Not common.
Æcidium Menthæ, DC. Mint Cluster-Cups; spots obliterated; subiculum thickened; peridia scattered, emersed, or aggregate immersed; spores orange, elliptic.—On various Mints. Common.
Æcidium Scrophulariæ, DC. Figwort Cluster-Cups; spots yellowish; peridia in roundish circinate clusters (rarely scattered) on the under surface; spores whitish, becoming tawny.—On the leaves of Scrophularia aquatica. Thame and Sydenham, Oxon.
Æcidium Pedicularis, Lobosch. Red-rattle Cluster-Cups; spots obliterated, subiculum thickened; peridia thickly and irregularly clustered, subimmersed; spores dirty, pallid orange.—On petioles, leaves, and stems of Pedicularis palustris. Not common.
Æcidium Primulæ, DC. Primrose Cluster-Cups; spots obliterated; peridia solitary, scattered, and crowded, hypogenous; spores whitish-yellow.—On the under surface of leaves of Primroses. Not common. May.
Æcidium rubellum, Pers. Dock Cluster-Cups; spots purple; peridia circinating, centre free; spores yellowish-white.—On leaves of Dock and Sorrel. Not uncommon in moist localities. May and June.
Æcidium Ari, Berk. Wake-robin Cluster-Cups; spots round, confluent; peridia circinating, not crowded, central ones abortive.—On leaves of Arum maculatum. Not common. June and July.
Æcidium Dracontii, Schwein. Arum Cluster-Cups; spots pallid, extensively scattered over the leaves, sometimes nearly covering them; peridia large, scattered, abundant, disposed without order on the spots; spores orange.—On Arum triphyllum, in gardens. Melbury, 1863 (Rev. M. J. B.) A North American species.
Æcidium Allii, Grev. Garlic Cluster-Cups; spots pale; peridia circinating, not contiguous; spores yellowish.—On leaves of broad-leaved Garlic (Allium ursinum). June and July.