Puccinia hyalostrata A.A. Carvalho & J.F. Hennen., 2018

De Carvalho-Junior, Anibal A. & Hennen, Joe F., 2018, Puccinia on Ipomoea (Convolvulaceae) in Neotropics, Phytotaxa 344 (2), pp. 133-148 : 137-138

4. Puccinia hyalostrata A.A. Carvalho & J.F. Hennen. sp. nov. Figure 2 A− E (Holotype).

MycoBank:—MB 819322

Type:― BRAZIL. Rio de Janeiro: Reserva Florestal Itatiaya, 9 May 1922, on Ipomoea sp. , E.W.D. Holway and Mary M. Holway 1851

(Reliq. Holw. 398!).

The new species can be readily distinguished from the other by the presence of urediniospores catenulate, finely verrucose with smooth spot, 26–33 × 22–25 μm, wall regularly thick; teliospores 51–64 × 29–36 μm, wall obviously two-layered, rounded above and below, not or slightly constricted at the septum.

Spermogonia and aecia unknown. Uredinia ( Aecidium type) scattered singly or in small groups on yellowish or brownish spots 1–2 mm across on abaxial side of leaves, sometimes very locally systemic on veins, peridium tubular, whitish, 1 mm long, peridial cells 27–37 × 15–28 μm, irregularly rhomboidal or polyhedral, wall 2.5–4 μm thick in face view, colorless, outer-facing wall smooth, inner-facing wall strongly verrucose-rugose; urediniospores 26–33 × 22–25 μm, globoid or broadly ellipsoid, wall (1.5–)2–3 μm thick, finely verrucose but usually with a noticeable smooth spot, colorless. Telia scattered singly or in groups, mainly on adaxial side of leaves, often by or within the old uredinia, sometimes up to 1 mm wide on veins, slightly pulverulent, blackish-brown, ruptured epidermis often noticeable; teliospores 51–64 × 29–36 μm, ellipsoid, rounded above and below, not or slightly constricted at the septum; wall obviously two-layered, outer layer pale yellow to hyaline, variable in thickness, (1–)1.5–2(–3) μm around the sides, (3–)4.5–8.5 μm above, verucose, inner layer dark golden- to light chestnut-brown, more or less evenly 2–3 μm thick; pedicel as long as or up to twice as long as the spore, colorless, slightly tinted next to the spore. Life cycle (?/?, IIcv, III).

Etymology —Comes from hyaline outer wall of teliospores, or hyaline outer stratus.

Additional specimen examined — BRAZIL. Rio de Janeiro, Theresopolis, 29 Sept 1921, on Ipomoea sp. , E.W.D. Holway and M. M. Holway 1170 (Reliq. Holw. 388!).

Notes and taxonomic affinities —This taxon is most easily identified by the two layers in the teliospore walls. The outer layer is hyaline or nearly so, and the inner layer is brownish. Only P.ibrae on Ipomoea has teliospore walls with such easily observed layers in the walls of the teliospores. However, P. hyalostrata also has an anamorph whose wall is regularly thick, and larger teliospores. Despite the great efforts expended by Salazar-Yepes & Carvalho (2010) in the same locality of the type, the species was not re-collected.

Figures

FIGURE 2. A−E. Puccinia hyalostrata (Holotype). A. Peridium. B−C. Urediniospores. B. Median focus. C. Surface focus. D−E. Teliospores. D. Median focus. E. Surface focus. F−H. P.ibrae. F−G. Urediniospores. F. Median focus. G. Surface focus; H. Teliospores in median focus. I−J. P. insignis (Holotype). I. Teliospores on median focus; above and left, peridium. J. Surface focus. K−M. P. iporangae (Holotype). K−L. Urediniospores. K. Median focus. L. Suface focus. M. Teliospores. Bars: A−I, M=20μm; K-L, J =10μm.