Diaphanopellis purpurea C. J. You & J. Cao, 2017

Cao, Jing, Tian, Cheng-Ming, Liang, Ying-Mei & You, Chong-Juan, 2017, A new rust species of Diaphanopellis on Rhododendron oreodoxa from Southern China, Phytotaxa 309 (1), pp. 55-65 : 60

Diaphanopellis purpurea C. J. You & J. Cao , sp. nov. ( Figs. 1 , 2 )

MycoBank:—MB819572

Etymology:—Epithet “ purpurea ” refers to the aecial host of the holotype.

Diagnosis: —Differs from morphologically similar species, Diaphanopellis forrestii in the surface structure of uredinospore and uredium peridium. In addition, it differs from other known Chrysomyxa species because of teliospore morphology.

Type:— CHINA, Sichuan Province: Kangding County, 29°59′36″N 101°53′46″E, alt. 3181 m, I on Picea purpurea Mast. ( Pinaceae ), 21 July 2014, C. J. You (Holotype, BJFC-R02299); CHINA, Sichuan Province: Kangding County, 29°59′36″N 101°53′46″E, alt. 3181 m, I on Picea purpurea : 21 July 2014, C. J. You (Isotype: BJFC-R02300).

Other Specimens examined:— CHINA, Sichuan Province: Kangding County, 22°59′24″N 101°52′39″E, alt. 3227 m, II, III on Rhododendron oreodoxa Franch. , 21 May 2014, Y. Bai ( BJFC-R01698 ) ; Yunnan Province: the National Forest Park of Shangari-La, 29°45′35″N 99°59′41″E, alt. 3565 m, I on Picea purpurea : 15 July 2014, C. J. You (BJFC- R02301 ; BJFC-R02302 ): CHINA, Sichuan Province, Kangding County, 29°59′21″N 101°52′40″E, alt. 3263 m, 21 May 2014, Y. Bai ( BJFC-R01699 ) ; Sichuan Province, Kangding County, May 1987, Y. L. Guo (HMAS-55188) .

Spermogonia unknown.

Aecia amphigenous, ligulate, 0.3–1.1 mm wide. Aeciospores ellipsoidal, oblong, globose, or subglobose, 16–28 × 11–24 μm, with yellow inclusion, densely echinulate, a small numbers of central spines arise frequently on a separated flat columnar verruca; wall hyaline, 0.4–0.6 μm thick, wall plus spines 1.2–3.4 μm thick; Aecial peridium dehiscing at apex, later shredding, leaving a fringe around sorus; Peridial cells rectangle, larger than the spores, outer surface deeply convex, striate or rugulose, inner surface flat, wall smooth. Uredinia subepidermal, erumpent, Aecidium-type, covered by a conspicuous peridium; Peridial cells polygonal, round or square, similar in size or larger than the spores; Outer peridium surface cells deeply concave, with sharply defined edges, smooth to slightly rough surface; inner surface flat or slightly convex, warts shallow, irregular, and discrete. Urediniospores catenulate, globose, subglobose to polygonal or ovoid, occasionally ellipsoidal, 22–38 × 20–30 μm, densely warted, warts coronate, fingerlike, flame-shaped or irregular in shape, the heads are acutely and minutely dentate or tubercular; wall 1.3–1.6 μm thick, wall plus warts 2.1–3.4 μm. Telia in large groups, gelatinous, orange or aurantiaca, erumpent; from round to elongated or irregular, 130–300 × 100–280 μm, often sunken in the center; raised, slightly constricted at the base, without stalk cells. Teliospores catenulate, 10–28 × 5–12 μm, thin-walled, finely tuberculate, enclosed in a loose hyaline sheath with a thin wall, not laterally adherent.

Figures

FIGURE 1. Diaphanopellis purpurea on Picea purpurea (BJFC-R02299). A. Oblong-ellipsoid aeciospores (LM); B. Aecial peridium with smooth inner surface; C. aeciospores; D. Aecial peridium with deeply convex, striate or rugulose outer surface; E. Densely echinulate on aeciospores surface. Scale bars: A, C, D, E = 10μm; B = 20 μm.

FIGURE 2. Diaphanopellis purpurea on Rhododendron oreodoxa (BJFC-R01698).A.Telia in large groups, gelatinous, orange, erumpent; B. Showing transparent sheaths extending beyond teliospores; C. Cross section of telium, showing transparent sheaths around teliospores; D. Globose to subglobose urediniospores; E. Urediniospores; F. Urediniospores showing warts coronate, fingerlike, or irregular in shape; G. Concave outer surface of peridial cells; H. Warted inner surface of peridial cells. Scale bars: A = 200 μm; B = 50 μm; C, D, E, G = 10 μm; F = 0.5 μm; H = 20 μm.