Ravenelia evansii Sydow, Ann. Mycol. 10, p. 440, Monograph. Ured. 3, p. 234

Ebinghaus, Malte, Maier, Wolfgang, Wingfield, Michael J. & Begerow, Dominik, 2018, New host associations and a novel species for the gall-inducing acacia rust genus Ravenelia in South Africa, MycoKeys 43, pp. 1-21 : 12-13

Ravenelia evansii Sydow, Ann. Mycol. 10, p. 440, Monograph. Ured. 3, p. 234 Figure 4J

Ravenelia evansii Sydow, Ann. Mycol. 10, p. 440, Monograph. Ured. 3, p. 234 On Vachellia borleae (Burtt Davy) Kyal. & Boatwr., V. davyi (N.E.Br.) Kyal. & Boatwr., V. exuvialis (I. Verd.) Kyal. & Boatwr., V. hebeclada (DC.) Kyal. & Boatwr., V. luederitzii var. retinens (Sim.) (JH Ross & Brenan) Kyal. & Boatwr. and V. swazica (Burtt Davy) Kyal. & Boatwr. ( Fabaceae : Mimosoideae).

Emended description.

Telia subepidermally erumpent, dark brown to blackish, scattered or in loose groups on the abaxial side of leaflets, sori on the comparatively large leaflets of V. robusta ssp. robusta often forming concentric rings of 2.2-3.3 mm in diameter, single sori (120)230-500(710) μm in diameter with the largest telia appearing to develop in concentric arranged groups, subcircular to elongated; paraphyses lacking; teliospores circular to subcircular from topview, topside convex to almost hemispherical from lateral view, chestnut brown, (47)74-103(124) μm in diameter with (3)5-7(8) probasidial cells in a cross-section; single probasidial cells mostly single-layered, sometimes central cells and in rare events single cells two-layered, (16)23-30(39) μm from lateral view and (11)18-25(34) μm from top view; each probasidial cell with 3-5(8) spines; cysts hyaline and smooth, uniseriate and each cyst appears to be divided by a faint constriction, of the same number as peripheral probasidial cells, swelling in water but only slightly in lactophenol, pedicels compound, not persisting.

Specimens examined.

All specimens examined for the emended species description of R. evansii representing new host associations are given in Table 1.

Notes.

Rust infections on specimens of Vachellia borleae (ME384, PREM61869), V. davyi (PREM61845, PREM61005), V. exuvialis (PREM61876, PREM61868), V. hebeclada (PREM61227), V. luederitzii var. retinens (PREM61846) and Vachellia swazica .(PREM61002, PREM61028, PREM61008) were identified using morphological characters of the teliospores. These generally matched those of R. evansii Syd. & P. Syd. given in Doidge (1927) and Shivas et al. (2013) and were supported by molecular phylogenetic analyses of nrITS and nrLSU sequence data. These Vachellia species are reported as new hosts for Ravenelia evansii . Despite major congruence of teliospore characters, the range of the teliospore diameter observed by our examinations exceeded the size range of 50-80 μm and 63-90 μm given in Doidge (1927) and Shivas et al. (2013), respectively. Furthermore, the occurrence of two-layered probasidial cells is reported here for the first time Figure 4J). Therefore, we present an emended description of the telial stage of R. evansii Syd. & P. Syd. emend. Ebinghaus, W. Maier and Begerow.