Puccinia rubicunda Holway (1904: 392)

De Carvalho-Junior, Anibal A. & Hennen, Joe F., 2018, Puccinia on Ipomoea (Convolvulaceae) in Neotropics, Phytotaxa 344 (2), pp. 133-148 : 145

12. Puccinia rubicunda Holway (1904: 392) .

≡ Allodus rubicund a (Holw.) Arthur & Orton (1921: 468).

Type:― MEXICO. Veracruz: near city Veracruz, 5 Oct 1898, on Ipomoea sp. ( I. intropilosa ?) from E. W.D. Holway 3084. Figure 4 D− H (Isotype).

Spermogonia and aecia unknown. Uredinia ( Aecidium type) on the adaxial side of leaves, often on yellowish or brown spots, scattered singly or in loose groups of varying sizes, sori 0.2–0.6 mm diameter, pulvinate, opening by a pore, peridium whitish, scarsely protruding above the overarching epidermis, peridial cells 32–40 × 16–20 μm, rhomboidal, the outer-facing wall 2.0–2.5 μm thick, smooth, the inner-facing wall 2.5–4 μm thick, conspicuously verrucose; urediniospores 23–29 × 19–23 μm, globoid, broadly ellipsoid, or ovoid; wall (2–)2.5(–3) μm thick, colorless, more or less evenly covered with large angular, flat verrucae (1.5–)2–3 μm across the top. Telia as the uredinia, but blackish-brown and lack peridia, at times developing next to or in the old uredinia, tardily pulverulent; teliospores 40– 47 × 27–32 μm, broadly ellipsoid, usually rounded at both ends, rarely slightly narrowed, not constricted at septum; wall 2.5(–4) μm thick, not or at times thickened to 6 μm above, not thickened at septa, dark vinous-brown, coarsely tuberculate; two pores in each cell, next to septum; pedicel up to 70 μm, colorless but slightly tinted next to spore ( Holway 1904; Arthur & Orton 1921). Life cycle (?/?, IIcv, III).

Specimen examined (Isotype)― MEXICO. Veracruz: near city of Veracruz, 5 Oct 1898, on Ipomoea fistulosa Mart. ex Choise, E.W.D. Holway 3084 (PUR36123!).

Distribution ― Puccinia rubicunda has been reported only from the type collection ( Holway 1904; Arthur & Orton 1921; Hennen & Cummins 1973).

Notes ―By examing the type material, we found some differences in the spore dimensions: urediniospores 19–26 × 23–31 μm; teliospores (40–)45–50(–56) × 24–35 μm. This species is distinct because the teliospores have two pores next to the septum in each cell and the urediniospore walls have flattened, coarse verrucae. Some other species of Puccinia on Ipomoea , as P. megalospora , also have two pores in the lower cell of the teliospores but they are usually obscure and not visible ( Arthur and Orton 1921).

Figures

FIGURE 4. A−C. P. opulentissima (Holotype). A. Urediniospores in median and surface focus. B−C. Teliospores. B. Median focus. C. Surface focus. D−H. P. rubicunda (Isotype). D. Peridium. E−F. Urediniospores. E. Median focus. F. Surface focus. G−H. Teliospores. G. Median focus. H. Surface focus. I−L. Puccinia superflua (Isotype). I−J. Urediniospores. I. Median focus. J. Surface focus. K−L. Teliospores. K. Median focus. L. Surface focus. Bars:A−C, I−J=10 μm; D−H, K−L=20 μm.