Studies in genera similar to Torula: Bahusaganda, Bahusandhika, Pseudotorula, and Simmonsiella gen. nov

Abstract

A generic key is presented to delimit Torula from seven hyphomycete genera whose type species were at one time included in the genus or whose conidium ontogeny and conidium development appear similar or superficially similar to that of Torula herbarum, the type of the genus. In Bahusaganda, two new species are described (B. elliseverhartii and B. simmonsii spp. nov.) and three new combinations made (B. ambrosiae, B. elaeodes, and B. heteromorpha combs. nov.). In Bahusandhika, one new species (B. hughesii sp. nov.) is introduced, and two new combinations made (B. rhombica and B. terrestris combs. nov.), along with emendations in the circumscription of B. caligans and B. intercalaris. Latorua is considered synonymous with Bahusandhika. In Pseudotorula, one new combination is made (P. sundara comb. nov.), and one emendation proposed (P. helica). The transfer of Dwayabeeja sundara, the type species of the genus, to Pseudotorula will require a new generic name to be introduced for D. aethiopica and D. cubensis. The new generic name Simmonsiella is established for Torula ndjilensis. Bahusandhika compacta is shown to be synonymous with Torula verrucospora.

Keywords: Bahuchashaka; Dwayabeeja; Latorua; Polyschema; corona cell.

Fig. 1.

Bahusaganda ambrosiae. A. Coronate conidiogenous cell (arrow) (Bartholomew 3508, holotype). B. Mature conidia (ILLS 59071). C. Polyblastic conidiogenous cell and two developing conidia (ILLS 59071). D. Corona cell on a stalk cell developing laterally on a hypha (Bartholomew 3508, holotype). E. Mature verrucose conidium (Bartholomew 3508, holotype). Bars = 10 μm.

Fig. 2.

Bahusaganda elaeodes. A–D. Conidiogenesis illustrating corona cells and developing conidia (ILLS 36106). C–D. Corona cells laterally attached to hyphae (ILLS 36106). E–H. Mature conidia and corona cells (holotype). I. Corona cell and subtending stalk cell laterally attached to hypha (holotype). J. Mature conidium and corona cells (holotype). K. Conidium cell illustrating verrucae (holotype). Bars: A–H & J = 10 μm, I = 5 μm, K = 1 μm.

Fig. 3.

Bahusaganda elliseverhartii (holotype). A–B. Conidiogenesis. A. Catenate series of corona cells with attached conidium. B. Conidia attached to corona cells. C–D. Mature conidia. Bars = 10 μm.

Fig. 4.

Bahusaganda heteromorpha (holotype). A. Conidiophores arising laterally on hyphae and usually terminated by a corona cell. B. Mature conidia. Bars = 10 μm.

Fig. 5.

Bahusaganda simmonsii (holotype). A. Mature conidium. B. Micronematous conidiophore with a mature, terminal corona cell and two laterally developing corona cells. C–D. Successive corona cells on terminal micronematous conidiophores. E–G. Mature conidia. Bars = 10 μm.

Fig. 6.

Bahusandhika caligans (holotype). A–C. Monoblastic and polyblastic conidiogenous cells illustrating immature solitary or catenate conidia. D–G. Mature solitary or catenate conidia. Bars = 10 μm.

Fig. 7.

Bahusandhika hughesii (holotype) A–B. Conidiophores with successive spherical or subspherical conidiogenous cells. C. Conidiogenous cells with conidia developing singly. D–F. Mature conidia. E–F. Catenate conidia. Bars = 10 μm.

Fig. 8.

Bahusandhika intercalaris (holotype). A. Extensively branched net–like hyphae with developing conidiophore (arrow). B. Two-celled conidiophore with a conidiogenous cell and a developing conidium. C–E. Chains of mature conidia illustrating the development of conidiogenous cells from the apical cell of conidia. F. Mature conidia. Bars = 10 μm.

Fig. 9.

Bahusandhika rhombica (holotype). A–C. Mature conidia. D–F. SEM micrographs of conidia and verrucae. Bars: A–E = 10 μm, F = 1 μm.

Fig. 10.

Bahusandhika terrestris conidiogenesis with mature conidia (holotype). A–B, D, F. Monoblastic conidiogenous cells. C, E. Polyblastic conidiogenous cells. Bars = 10 μm.

Fig. 11.

Pseudotorula helica. A. Conidiophores developed laterally on a hypha and each terminated by a corona cell (holotype). B. Mature phragmoconidia, arrows show corona cells at apex of two conidia (DAOM 96014e). C–D. Scolecoconidia illustrating the helical arrangement and the extensive melanization and periclinal thickening of the wall (holotype & DAOM 96014e). E. Enlargement of cells of a scolecoconidium illustrating periclinal thickening of the wall and melanization of the wall and septa (DAOM 96014e). Bars: A–D = 10 μm, E = 5 μm.

Fig. 12.

Pseudotorula sundara (holotype). A, D, F. Phragmoconidia. A. inset a 2-septate conidium. B–C. Phragmoconidia in chains from polyblastic corona cells (arrows). E. Conidiophore with a corona cell. G. Scolecoconidium. H. Scolecoconidium with developing phragmoconidia from corona cells (arrows). I. Phragmoconidium from a monoblastic corona cell (arrow) at apex of a conidium. Bars = 10 μm.

Fig 13.

Simmonsiella ndjilensis (holotype). A–B. Mature, solitary and catenate conidia (arrows). C. SEM illustrating catenate conidia with intercalary hypha (arrow). D. SEM of mature conidium. E. SEM of enlarged wall of a conidium illustrating hollow and collapsed verrucae. Bars: A–B = 10 μm, C–D = 5 μm, E = 1 μm.

Fig 14.

Torula verrucospora (holotype of Bahusandhika compacta). A. Hyphae with lateral and terminal corona cells and 3-septate conidia. B–C. Chains of immature 1-septate and mature 3-septate conidia from monoblastic or polyblastic corona cells. Bars = 10 μm.