Puccinia distinguenda H. S. Jacks. & Holw.

De Carvalho-Junior, Anibal A. & Hennen, Joe F., 2018, Puccinia on Ipomoea (Convolvulaceae) in Neotropics, Phytotaxa 344 (2), pp. 133-148 : 136-137

3. Puccinia distinguenda H. S. Jacks. & Holw. in Jackson (1931: 497) [as “ Puccinia distinguenda (Syd.) H. S. Jacks.

& Holw.”].

≡ Puccinia puta H. S. Jacks. & Holw. , ex F. Kern, Thurston and Whetzel (1933: 477), (Nom. nov. for P. distinguenda (Syd.) H. S. Jacks. & Holw. ).

Type:― ECUADOR. Guayaquil, 30 July 1920, on Ipomoea fistulosa Mart. ex Choisy, Holway 794. Teleomorph described. Not Puccinia distinguenda Sydow & Sydow. (1908: 482) . Figure 1 J− N (Holotype). = Aecidium distinguendum P. Sydow. & Sydow (1924: 131) . Type:― PERU. Tarapoto, on Ipomoea sp. , Ule 3244. = Puccinia agnesiae Sydow (1934: 288) , (Teleomorph not described). = Aecidium agnesiae (Syd.) Urban (1990: 48) . Type:― BRAZIL. Bahia, Rio Salitre, 46 Km west-southwest of Joazeiro, 15 Dec. 1924, on Ipomoea crassicaulis (Benth.) B.L. Rob., Agnes

Chase 7942.

Spermogonia and aecia unknown. Uredinia ( Aecidium type), mostly on abaxial side of leaves, solitary or in dense groups 1–4 mm across, cupulate, peridial cells 24–34 × 15–18 μm, wall uniformily 4–6 μm thick, outer wall delicately striate, inner wall verrucose, urediniospores 24–30 × 20–26 μm, catenulate, angular–globoid, wall 1.5–2 μm thick at sides, apical walls up to 8 μm or thicker, verrucose, warts 1(–1.4) μm apart. Teliospores 42–56 × 28–32 μm, ellipsoid or oblong, rounded above and below, or sometimes obtuse above, not constricted at septum, lateral wall 3.5–4 μm thick, apical wall 5–6 μm and at angles formed by septum, dark chestnut- to blackish-brown, verrucose, warts (1.5–)2–2.5(–3) μm apart; pedicel equal to or twice the length of spore, colorless or slightly tinted next to spore, 10–11 μm thick at point of attachment, soon collapsing ( Jackson 1931; Sydow and Sydow 1924). Life cycle (?/?, IIcv, III).

Specimen examined (Holotype)― ECUADOR. Quayaquil, 30 July 1920, on Ipomoea fistulosa Mart. ex. Choisy, E.W.D. Holway 794 (PURF7143!).

Distribution ― Puccinia distinguenda has been reported also from Peru ( Sydow & Sydow 1924), Ecuador ( Jackson 1931; Sydow 1939), Colombia ( Kern et al. 1933; Pardo-Cardona 2002), Venezuela ( Frank et al. 1934; Kern 1938), Puerto Rico and Mexico ( Hennen & McCain 1993; Farr & Rossman 2015), Brazil ( Sydow & Sydow 1924; Batista et al. 1966), Cuba ( Urban 1990).

Notes ― Sydow (1934) suggested the name Puccinia agnesiae without teliospore description. Urban (1990) gave the new name Aecidium agnesiae to P. agnesiae because the specimen has no teliospores, but another anamorphic name already existed, Aecidium distinguendum .

Unlike Sydow (1934) who understood that A. agnesiae differs from A. distinguenta by urediniospore size, length and width of the wall, our analysis showed no significant differences between these two species; we therefore placed the species as synonyms.

By examining the type material, we found some differences in the spore dimensions: urediniospores 33–40 × 24–33 μm; teliospores 56–61 × 33–37 and lateral wall with (2–)2.5–3.5(–4), but this does not imply changes in the taxon identification.

Two other species of rust on Ipomoea from the neotropics with Aecidium-type uredinia have apically thickened urediniospore walls: P. nocticolor has been reported from Mexico on shrub or tree species of Ipomoea , and P. ibrae on vine species of Ipomoea from Mexico and Honduras. However, in other respects, these species differ significantly from P. distinguenda .

Figures

FIGURE 1. A−D. P. crassipes (Holotype). A−B. Urediniospores.A. Median focus. B. Surface focus. C−D. Teliospores. C. Median focus. D. Surface focus. E−I. P. cuasoensis (Holotype). E. Peridium. F−G. Urediniospores. F. Median focus. G. Surface focus. H−I. Teliospores: H. Median focus. I. Surface focus. J−N. Puccinia distinguenta (Holotype). J. Peridium. K−L. Urediniospores. K. Median focus. L. Surface focus. M−N. Teliospores. M. Median focus. N. Surface focus. Bars: A−D, J−N=20μm; E−I=10μm.