The genus Trichosterigma Fetch. T. Fetch. 93 



THE GENUS TRICHOSTERIGMA FETCH. 



By T. Fetch. 



In the Transactions of the British Mycological Society, viii, 

 p. 215, the \\Titer proposed a new genus of Stilbaceae, Tricho- 

 sterigma, for the reception of three species of fungi parasitic 

 on insects. It has since, however, transpired that a genus was 

 founded on a fimgus similar to these several years ago, and the 

 name Trichosterigma must consequently be discarded. 



In 1912, Speare pubhshed an account of the fungi parasitic 

 upon insects injurious to sugar-cane in Hawaii (Biill. No. 12, 

 Pathological and Physiological Series, Hawaiian Sugar Planters' 

 Association), in which he described and figiu-ed, under the 

 heading "Sterile Cordyceps," a conidial fungus parasitic on a 

 leaf hopper. Subsequently, Speare further investigated this and 

 other similar fungi, and came to the conclusion that they should 

 be included in the genus HirsuteUa Pat. Speare's account of 

 these species of HirsuteUa was published in a paper entitled " On 

 certain entomogenous fungi," in ^lycologia, xii (pp. 62-76, 1920). 



The genus HirsuteUa was established by PatouiUard in 1S92 

 (Rev. Mvc. XIV, p. 69) on a species, HirsuteUa entomophila, which 

 was found on an undetermined coleopteron in Ecuador. The 

 fimgus formed erect clavae, covered with scattered ovoid basidia, 

 each basidium bearing a single elongated sterigma, ^^■ith a single 

 terminal, lemon-shaped spore. Patouillard noted that the 

 basidia were scattered, and that there was no subh\Tnenium, 

 but he nevertheless regarded the fungus as a Basidiomycete, 

 and included in the Clavariaceae. In his Essai Taxonomique 

 (1900), Patouillard extended the genus to include species with 

 tetrasporous basidia. 



There does not appear to be any doubt that Speare's con- 

 clusion is correct, and that HirsuteUa entomophila, the t^/pe 

 species of the genus, is a Hyphomycete. Speare has also sho\\Ti 

 that the actual spore is elongated or fusiform, and that the 

 "citriform" appearance is due to a covering of mucus deposited 

 round the spore in such a way as to render it unifonnl}' lemon- 

 shaped. Spores may be found lacking this mucous covering, 

 or it may have sagged down to the base of the spore so that the 

 whole appears obcordate. 



Trichosterigma Petch is s\TiomTnous \rith HirsuteUa Pat. Of 

 the species described by me [lac. cit.), Trichosterigma attenuatum 

 Petch = HirsuteUa citriformis Speare. Trichosterigma clavi- 

 sporum Petch and Trichosterigmei arachnophilum Petch must be 

 known as HirsuteUa clavispora and HirsuteUa arachnophila 

 respectively. 



