PERSOONIA Published by the Rijksherbarium, Leiden Volume Part 2, 3, pp. 407-415 (1962) New genera of Fungi—VIII Rolf Singer Universidad de Buenos Aires The based structure of with genus Pseudohiatula, on hymeniform epicutis interspersed dermatocystidia or trichodermial-palisadic structure without all in tribus dermatocystidia, contains species, belonging the same (Marasmieae), but does not seem to be sufficiently homogeneous to be restricted maintained sensu lato. It is now to the type species (P. cyatheae), and P. is united with in the callistosporioides Cyptotrama macrobasidium genus Cyptotrama; P. irrorata and P. panamensis (perhaps also P. ohshimae) are referable to Hydropus (where species with projecting dermatocystidia and with muricate pleurocystidia should be admitted); P. conigenoides, esculenta, and tenacella in and stephanocystis, are placed a new genus, Strobilurus, P. cinnamomea in another new genus, Physocystidium. The Pseudohiatula is characterized of the genus by a very specific structure epicutis which consists of a corticate hymeniform layer of rather broad elements, with larger dermatocystidia interspersed. On the basis of the species known formerly and under of the characters of the until consideration type species known recently, the species ofMarasmieae (Tricholomataceae) with this particular cuticular structure appeared to form a fairly homogeneous group corresponding to an emended concept of the Pseudohiatula such circumscribed in modern genus as in my book 'Agaricales taxonomy', 2nd ed., C. Cramer, Weinheim/Bergstr., Germany, 1962. A revision of the type element of the genus Pseudohiatula has become possible because ofthe discovery of the respective species in Brazil (Singer in Vellozia,i962), but the corresponding readjustment in the generic taxonomy of the Tricholo- the affinities mataceae—Marasmieae has been postponed until more data on of the other species entering Pseudohiatula in the classification of 1962 became available. This VIII of'New is also the reason for the delayed publication of the present part of genera fungi'. However, it is now possible to discuss the affinity of these species in their relation the to type species, Pseudohiatula cyatheae, and in their relation to other genera of the same tribus. We are now convinced that, within Pseudohiatula in its conception of there five elements which divided from 1962, are groups or are not necessarily other of genera the same tribus by a hiatus more evident or sharper than the one that divides them each other. In other it be admitted that among words, must 1 Earlier parts of this series have been published as follows: I in Mycologia 36: 358-368. — II in — 8: III in — IV in 1944. Lloydia 139-144. 1945. Mycologia 39: 77-89. 1947. Mycol- — V in — VI in ogia 40: 262-264. 1948. Mycologia 43 : 598-604. 1951. Lilloa 23: 255-258. — VII in 1951. Mycologia 48: 719-727. 1956. 407 Persoonia Vol. Part 408 2, 3, 1962 Pseudohiatula lato is sensu (1962) perhaps an example of a genus in which too much has been weight given to a single anatomical character—thestructure ofthe cuticular of the in layer pileus—whereas reality, other characters, thus far considered as secondary, to show that the should be restricted appear genus to the only original and the other elements species be separated generically from it. This is a situation the comparable to one prevailing in the case of Cantharellula sensu lato, which also had to be into number ofrelated split up a genera (see 'New genera offungi—VII'). The principal elements of Pseudohiatula sensu lato are: (1) The P. type, cyatheae (Sing.) Sing., with amyloid spores, bilateral trama, with irregularly occurring clamp connections, with insititious stipe, habit of a mycenoid-pluteoid agaric, with fuscous intracellular pigment and rounded-free lamellae, growing on Pteridophyta (tree ferns) in the tropics (and in hothouses). P. with (2) callistosporioides Sing, (in print) vaguely pseudoamyloid spores which become slightly pigmented in age, bilateral trama, with constant clamp connections, with basal mycelial fibrils, habit collybioid, with ochraceous-melleous incrusting membranal or pigments and rounded-adnexed or subfree (to broadly adnate) wood Alnus in lamellae, growing on dicotyledonous ( jorullensis) the (sub-) tropics. (3) P. with all the characters of conigenoides (Ellis) Sing, principal the group of boreal species inhabiting conifer cones (but growing on Magnolia cones), with small which remain of the inamyloid narrow spores hyaline, regular trama Clitocybe- subtype, without clamp connections, with basal pseudorrhiza, habit collybioid, with of frequent crystalline incrustations on the tips the multinucleate cystidial •elements of hymenium and covering layers, growing in the cold-temperate to warm- of the Northern temperate zones hemisphere. (4) P. irrorata (Pat. apud Duss) Sing, with inamyloid spores, regular trama of the Clitocybe- subtype, with irregularly occurring clamp connections, without with pseudorrhiza, but with sparse mycelial basal fibrils, frequent crystalline incrustations the the latter habit on hymenial cystidia, pseudoamyloid, collybioid, wood in the growing on tropics. of tricho- (5) P. cinnamomea (Dennis) Sing, with aberrant epicutis, consisting a dermial palisade of multiseptate elements with pigmented walls and without differentiated dermatocystidia, with regular trama, with numerous clamp connec- tions, without pseudorrhiza, with broad non-muricate cystidia, habit collybioid, lamellae adnate, growing on wood in the tropics. The whether these additional elements (2-5) are close enough question comes up in the referable to existing genera to be incorporated latter, or to new genera to be described for them. This question cannot be answered for all these species in the same way. As for with P. it that this is not generically group 2, callistosporioides, appears bilateral viz. separable from another genus with hymenophoral trama, Cyptotrama 30: with the C. macrobasidium We Sing, (in Lilloa 375. i960), type species Sing. therefore add to it, as second species, C. callistosporioides Sing., ined. Singer: —Vlll New genera 409 has been with does Group 3 repeatedly compared Marasmius, sect. Alliacei, yet fit into the section the of number of not seem to genus or on grounds a characters, such as constant absence of clamp connections, combined and correlated with the of the ofmuricate-incrusted and dermato- presence a pseudorrhiza, presence cystidia cystidia, etc. Since there is likewise no other genus described until now where the species of this group might reasonably enter, we are proposing the following new genus: Strobilurus Sing., gen. nov. Habitu collybioideo-submarasmioideo, epicute hymeniformi, dermatocystidiis in pileo et stipite praesentibus, cystidiis hymenialibus muricatis; sporis inamyloideis, subminutis, angustis, levibus; tramate hymenophorali regulari typi Clitocybarum, hyphis defibulatis; pseudorrhiza praesente, e conis Magnoliae et coniferarum variarum orta. Typus generis: S. conigenoides (Ellis) Sing., comb. nov. (Agaricus conigenoides Ellis in Bull. Torr. bot. CI. 6: 76. 1876). Aliae species sunt: S. esculentus (Wulf. ex Fr.) Sing., comb. nov. ( Agaricus esculentus Wulf. ex Fr., comb. Syst. mycol. i: 131. 1821); S. stephanocystis (Hora) Sing., nov. (Pseudohiatula stephano- Hora in Trans. Brit, Soc. S. tenacellus cystis mycol. 43: 455. i960); (Pers. ex Fr.) Sing., tenacellus comb. nov. (Agaricus Pers. ex Fr., Syst. mycol. 1: 131. 1821). The generic position of group 4 (P. irrorata) is obviously in the genus Hydropus, of provided an emended description of this genus and the incorporation a new section is permitted. This is so because the not truly bilateral gill trama, the fuscous intracellular pigment of the epicutis, the pseudoamyloid pleurocystidia, and the non-insititious in the of adnate lamellae and stipe place P. irrorata group species in admitted in with inamyloid spores recently (Singer Vellozia, 1962) Hydropus ² as section Mycenoides Sing, from which P. irrorata differs in muricate cystidia and long dermatocystidia on the pileus; parts of the trama are gelatinized. It will be noticed that the in its certain extension in genus Hydropus present circumscription, a of in the of the and is and it range structure epicutis hypodermium permitted, would not seem correct to exclude P. irrorata on the basis of the dermatocystidia for the muricate it will be or the gelatinized hypodermial hyphae. As cystidia, noted that in where these without murication with most genera exist, species (or a strongly reduced one) are likewise admitted. the section: Consequently, we propose new Hydropus, sect. Irrorati Sing., sect. nov. Sporis inamyloideis; hypodermio gelatinoso; epicute dermatocystidiis permagnis ornata; fibulis cystidiis hymenialibus laterum lamellarum nec non ad aciem crystallis muricatis; sparsis, interdum nullis(?). Typus sectionis: H. irroratus (Pat. apud Duss) Sing., comb. nov. irrorata Pat. Enum. meth. Mart. — It (Collybia apud Duss, Champ. Guad. 49. 1903). appears probable that Marasmius ohshimae Hongo & Matsuda [Pseudohiatula ohshimae (H. & M.) H. & M. ex Hongo] is another species of this section. As for the fifth of elements attached Pseudohiatula group formerly to sensu lato, viz. P. find related cinnamomea, we cannot any closely genus or section, except, Alliacei with have it perhaps, again Marasmius sect. which we compared recently 2 The reader is herewith asked to correct a printing error in 'Agaricales in modern taxonomy', 2nd ed., p. 389, line 4, where the spores should