Spiropes helleri (F. Stevens) M.B. Ellis, Mycol. Pap. 114: 14, 1968

Bermudez-Cova, Miguel A., Hofmann, Tina A., Yorou, Nourou S. & Piepenbring, Meike, 2024, Systematic revision of species of Atractilina and Spiropes hyperparasitic on Meliolales (Ascomycota) in the tropics, MycoKeys 103, pp. 167-213 : 167

Spiropes helleri (F. Stevens) M.B. Ellis, Mycol. Pap. 114: 14, 1968

Fig. 13

Helminthosporium helleri ≡ Helminthosporium helleri F. Stevens [as ' Helmisporium ], Bot. Gaz. 65(3): 242, 1918.

Helminthosporium leucosykes = Helminthosporium leucosykes H.S. Yates [as ' Helmisporium leucosykeae '], Philipp. J. Sci., C, Bot. 13(6): 382, 1918.

Helminthosporium maculosum = Helminthosporium maculosum Sacc. [as ' Helmisporium '], Atti Accad. Sci. Ven.-Trent.-Istr. 10: 91, 1919 [1917].

Pleurophragmium maculosum ≡ Pleurophragmium maculosum (Sacc.) S. Hughes, Can. J. Bot. 36: 797, 1958.

Description.

Colonies effused, dark brown to black, hairy. Hyphae superficial, branched, septate, 1-3 µm wide, straw-coloured or pale brown, smooth. Conidiophores arising singly as terminal or lateral branches on the hyphae, erect, straight or flexuous, septate, up to 600 µm long, 5-8 µm wide, brown to dark brown, paler towards the apex, smooth, with scattered conidial scars. Conidia solitary, obclavate, frequently rostrate, 3(-4)-septate, (26-)36-43(-50) × (6-)7-10(-13) µm, 3-4 µm wide at the truncate base, pale brown to brown, verruculose. As seen by SEM, the ornamentation of the spores is clearly reticulated, with thin networks and no ridges.

Specimens examined.

On Meliola sp. on leaves of Cupania guatemalensis ( Sapindaceae ), Panama, Chiriquí Province, Botanical Garden of the Autonomous University of Chiriquí (UNACHI), 8°25'55"N, 82°27'03"W, 34 m a.s.l., 11 February 2020, M. A. Bermúdez-Cova, A. Sanjur MB92 (UCH15489, M); on Meliola sp. on living leaves of Pterocarpus santalinoides ( Fabaceae ), Benin, Atlantique, Attogon, Niaouli Forest , 6°44'40"N, 2°7'53"E, 72 m a.s.l., 20 September 2022, A. Krauß, A. Tabé, O. Koukol, N.S. Yorou, AK15 (M) .

Additional specimens examined.

On Meliolales on living leaves of an undetermined plant, Gold Coast Colony, Banau, 1949, S.J. Hughes 1141 (IMI44564); on Meliola sp. on leaves of Myrcia deflexa , Puerto Rico, El Alto de la Bandera, F.L. Stevens 8268 (IMI9991, type of Helminthosporium helleri ) .

Illustrations.

This species was illustrated by Ellis (1968).

Known hosts and distribution.

On colonies of Asteridiella spp., Irenopsis spp. and Meliola spp. on living leaves of various plants in Ghana, Malaysia, New Caledonia, Philippines, Puerto Rico, Sabah, Sierra Leone and Uganda ( Ellis 1968). Spiropes helleri is reported here for the first time for Benin and for mainland America (Panama).

Notes.

Spiropes helleri is similar to S. effusus , S. dorycarpus and S. leonensis by the presence of obclavate to sometimes fusiform conidia, but differs from the first two by wider conidia (3.8-4.5 µm in S. effusus and 5-7 µm in S. dorycarpus ) and from the last one by narrower ones (10-11µm).

Figures

Figure 13. Spiropes helleri (IMI 130940) a superficial hyphae growing on a colony of Meliola sp. on a leaf of Cupania guatemalensis b conidiophore growing on a hypha of Meliola sp. shown in optical section c conidia shown in optical section (drawing on the left-hand side) and as seen by SEM (drawing on the right-hand side) d, e as seen by SEM d part of a conidiophore with a scar e conidium. Scale bars: 1 mm (a); 5 μm (b); 6 μm (c); 4 μm (b); 5 μm (c).