Spiropes palmetto (W.R. Gerard) M.B. Ellis, Mycol. Pap. 114: 16, 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 palmetto (W.R. Gerard) M.B. Ellis, Mycol. Pap. 114: 16, 1968

Fig. 19

Helminthosporium palmetto ≡ Helminthosporium palmetto W.R. Gerard, Grevillea 17(83): 68, 1889.

Pleurophragmium palmetto ≡ Pleurophragmium palmetto (W.R. Gerard) S. Hughes, Can. J. Bot. 36: 778, 1958.

Description.

Colonies effuse, dark brown to black, hairy. Hyphae superficial, branched, anastomosing, septate, 1-4 µm wide, pale olivaceous-brown, smooth. Conidiophores arising singly or in groups, as terminal and lateral branches on the hyphae, erect, straight or flexuous, septate, up to 400 µm long, 6-10 µm thick, dark brown, paler towards the apex, smooth, with scattered conidial scars. Conidia solitary, obclavate to fusiform, rostrate, with 2 septa delimiting a barrel-shaped central cell and often with an additional dark central pseudoseptum, (27-)30-46 × (7-)9-12(-15) µm, 3-5 µm wide at the truncate base, brown, middle cells pale brown, smooth as seen by LM and SEM.

Specimens examined.

On Meliola sp. on leaves of Elaeis guineensis ( Arecaceae ), Ghana, Apremodo, 1949, S.J. Hughes 534 (IMI 38617); on Meliola sp. on leaves of Sabal palmetto ( Arecaceae ), U.S.A, Louisiana (IMI 10032, type of Helminthosporium palmetto ) .

Illustrations.

This species was illustrated by Ellis (1968).

Known hosts and distribution.

On colonies of Irenopsis spp. and Meliola spp. on living leaves of various plants in Ghana, Malaysia, New Zealand, Puerto Rico, Sierra Leone and the U.S.A. ( Ellis 1968).

Notes.

Spiropes palmetto can be easily recognised by the presence of conidia with two septa that delimit a barrel-shaped central cell and with a dark central pseudoseptum ( Ellis 1968).

Figures

Figure 19. Spiropes palmetto (IMI 10032) a conidiophore growing on a hypha of Meliola sp., shown in optical section b conidia shown in optical section. The thickness of the walls is only shown in the two last drawings c, d as seen by SEM c part of a conidiophore with a scar d conidium. Scale bars: 7 μm (a); 5 μm (b); 6 μm (c); 7 μm (d).