Bot. [L. ūrēdo (pl. ūrēdinēs) blight, blast, itch, f. L. ūrĕre to burn.]
1. A form of blight, = BRAND sb. 7. rare.
1706. Phillips (ed. Kersey), Uredo, the blasting of Trees or Herbs.
1728. Chambers, Cycl., s.v. Disease, Diseases of Plants…. 9. Uredo, or Scorching, of which there are two Kinds.
1832. Lindley, Introd. Bot., 299. Albigo, ferrugo, and uredo, commonly called mildew, smut, rust, brand, and other names, are diseases caused by the presence of myriads of minute fungi.
2. A name for various fungi (popularly called rust, smut, mildew, etc.) parasitic on grain and certain other plants; formerly regarded as a distinct genus, but now known to be only the intermediate stage of the Uredineæ or rust fungi (cf. UREDOSPORE). Usu. with capital.
1836. M. J. Berkeley, Fungi, 369. The specimens are referred by Klotzsch to Uredo.
1843. Penny Cycl., XXVI. 47/1. The wheat became attacked with Uredo.
1889. Plowright, Brit. Uredineæ, 125. The Uredo and Uromyces frequently attack the petioles.
b. A species or plant of this.
1836. M. J. Berkeley, Fungi, 375. Elongated Uredo … Parallel Uredo.
1843. Penny Cycl., XXVI. 47/1. He diffused the granules of a Uredo in water.
1849. Lancet, 17 Nov., 531/2. The uredo is studded all over with sharp points.
1889. Berwick. Nat. Club’s Proc., XII. 488. A brown Uredo or Puccinia of the Common Mallow.
c. A receptacle or hymenium in which uredospores are formed. rare–1.
1879. Encycl. Brit., IX. 831/2. Again, in a few days, this mycelium forms a new kind of receptacle, the uredo.
3. attrib., as uredo-form, -patch; uredo-fruit, a group of uredospores; uredo stage, the summer stage of certain rust fungi.
1875. Bennett & Dyer, trans. Sachs’s Bot., 243. While the Fungus is multiplying … during the summer in its *uredoform, the production of a new form of spores begins in the older *uredo-fruits.
1887. Bentley, Man. Bot. (ed. 5), 38. These uredo-fruits consist of a dense mycelium [etc.].
1887. Hillhouse, trans. Strasburger’s Pract. Bot., 265. The haulm of an oat which is infected with rusty *uredo-patches.
1880. Bessey, Bot., 316. Later in the season … the *uredo stage begins to make its appearance … upon the leaves.
1895. M. C. Cooke, Study Fungi, xx. 246. In this group [sc. Pucciniopsis] of species the uredo stage is deficient.
