PERSOONIA Published by the Rijksherbarium, Leiden Volume Part 8, 3, pp. 329-333 (1975) Notes and brief articles The perfect state of Tilachlidiumbrachiatum W. Gams Centraalbureau voor Schimmelcultures, Baarn The morphology and nomenclature of the characteristic, probably monotypic, stilbellaceous Tilachlidium dealt with Petch hyphomycete genus Preuss has been by (1937) and Gams (1971: 141). A perfect state was then unknown. Colonies of the fungus in vitro are rather similar to those of Nectria viridescens Booth. The conidial with state has now been found in nature connected a hypocreaceous (nectriaceous) perfect state. tilachlidii Pseudonectria W. Gams, spec. nov. in inter Perithecia agarico putrido superficialia synnemata conidialia sparsa, subglobosa, ad minusve ramosis ochracea, 175-185X160-175 /im, hyphis albidis, 40 /urn longis, plus in asci fimbriata; paries 12-15 /im crassus, extus ochraceus, tus hyalinus; anguste clavati, modice diam. minusve tenuitunicati, sursum truncati, circa 50 fim longi, 5 /im Ascosporae plus biseriatae, continuae, anguste clavatae, basi truncatae, modice curvatae, tenuitunicatae, Status conidialis Tilachlidium leves, hyalinae, 6-8x1.5-1.8 /tm. brachiatvm (Batsch per Fr.) Petch. H. A. der Oct. Typus: van Aa, prope Baarn, 10 1974 (Herb. CBS 178). Perithecia amidst superficial on decaying agaric, scattered, partly aggregated, conidial synnemata, subglobose, generally 175-185 /am high, 160-175 /<m diam., ochraceous, covered with whitish, sometimes basitonously branched, warted, fringe- like to Perithecial wall of hyphae, up 40 /im long. 12-15 >im thick, consisting 5-6 of flattened the layers cells, outer ones slightly pigmented. Asci lining the base and sides of the perithecial cavity, slender clavate, thin-walled, with slightly truncate and apex minute apical structure, approximately 50 nm long, pars sporifera 25 /im and diam. filiform. less long up to 5 /im Paraphyses scarce, Ascospores more or biseriate, one-celled, narrowly claviform, with truncate base, mostly slightly curved, thin and very smooth-walled, hyaline, 6-8.5 x I -5~'-8 /<m. Conidial Tilachlidium The state brachiatum (Batsch per Fr.) Petch. conidia are curved and shorter than the in vitro elongate, never ascospores, 3.2-4.5 fim long, up to 7.5 jum. MATERIAL EXAMINED. — H. A. van der Aa, on decaying agaric near Oct. CBS swimming pool 'De Vuursche', Baarn, 10 1974 (Herb. 178). Isolations from thoroughly washed and squashed mature perithecia yielded numerous homo- geneous cultures identical with those isolated from the conidial state (CBS 697.74). 329 PERSOONIA Vol. Part 330 8, 3, 1975 Fig. 1. Pseudonectria tilachlidii. — a. Perithecium X 100. — b. Perithecial hairs. — c. Ascus — d. Part of with conidia and ascospores. synnema (b-d X 1000). DISCUSSION Arx Miiller and Arx According to Rogerson (1970), von & (1973) von (1974), the Pseudonectria Seaver. have been described fungus keys out as a Seventy-eight species in this genuswith its synonyms Nectriella Sacc. (non Nitschke) and Notarisiella (Sacc.) Clem. & Shear, amongst which N. mycetophila (Peck) Sacc. grows on decaying fungi but has of Because of the association with the Tilachlidium spores 12-13X 4 pm. conidial confusion with described be ruled The state, a specific a species can out. i.a. type species, P. rousseliana (Mont.) Seaver apud Clem. & Shear, redescribed by which Bezerra (1963), has light green perithecia covered with stiff hyaline setae exude red their P. rousseliana has asci and droplets at tips. larger perithecia, spores than the the fusiform with rounded present species; ascospores are ends, usually — the conidial state is Volutella buxi Berk. The conidial 13 1 5.5X3.0-4,0 (im; (Corda) state of Nectriella coronata Juel is Sesquicillium buxi (Schmidt apud Link) W. Gams (Juel, 1925). In other species the connection with conidial states has not been studied. Tilachlidium is the third genus of phialidic conidial states observed in the genus is Earle Earle Pseudonectria. Another close genus Allantonectria apud Tracy & (1901), of has immersed in basal the type species which, A. yuccae Earle, perithecia partly a leaves and allantoid stroma on ascospores. REFERENCES The in culture Vaduz. ARX, J. A. VON (1974). genera of fungi sporulating pure (2nd Edition). BEZERRA, J. L. (1963). Studies on Pseudonectria rousseliana. In Acta bot. neerl. 13: 58-63. Notes and Brief Articles 331 GAMS, W. (1971). Cephalosporium-artige Schimmelpilze (Hyphomycetes). Stuttgart. H. O. IX. In Ark. Bot. JUEL, (1925). Mykologische Beiträge 19 (20): 1-10. MÜLLER, E. & ARX, J. A. VON (1973). Pyrenomycetes: Meliolales, Coronophorales, Sphaeria les. In AINSWORTH, G. G. & al. (Eds.), The Fungi. An advanced treatise IV A: 87- New York and 132. London. PETCH, T. (1937). Notes on entomogenous fungi. In Trans. Br. mycol. Soc. si: 34-67. ROGERSON, C. T. (1970). The hypocrealian fungi (Ascomycetes, Hypocreales). In Mycologia 62: 865-910. S. & F. S. Plantae Bakerianae. Vol. TRACY, M. EARLE, (1901). II, Fungi, p. 1-30. Washington..