PERSOONIA Published by the Rijksherbarium, Leiden Part Volume i, i, pp. 21-23 ( ! 959) A species of Septobasidium shedding its immature basidia K.B. Boedijn The Hague (With five Text-figures) in relation with which the A new species of Septobasidium is described, of the Uredinella is discussed. position genus examination On two occasions a Septobasidium was found which on microscopical showed large numbers of free basidia. It could be demonstrated that these break off from the probasidia when still in the unseptate condition. Afterwards septa are As the formed, after which each cell produces a basidiospore on a short sterigma. species seems new, the following description is given. Septobasidium planum Boedijn, nov. spec. Fructificatio resupinata, hypophylla, suborbiculata, 7-22 mm diam. Margo plana, pallide media ad vel brunnea, elevata, usque 1 mm alta, fusca, ex hyphis solitariis fasciculatis erectis, brunneis, septatis, crasse tunicatis, 7-8 fi diam. formata. Probasidia pedicellata, globosa, pallide brunnea, 15-18 n diam. Basidia recta, simplicia, decidua, deinde 3-septata, _ 53 65 x 6.5-10.5 /i. Sterigmata 4-5.5 X 1.5-2.5 /(. Sporae fabiformes, 15-20 X 6-7 /<. Typus: Java, Bogor, Hortus botanicus, Sept. 1956 (Herb. Boedijn). The colonies are rounded to irregular in outline, 7—22 mm across, bordered by flat which is brown wood a typical, very margin greyish (about brown, Ridgw.), broad. In the less threads and 1-7 mm, usually 4-5 mm, centre more or erect fascicles of threads form slightly elevated portions which cover the scale insects which the Sometimes there number of such raised upon fungus grows. are a parts which dark with are brown (about natal brown, Ridgw.), irregular in shape or a lobed outline, 3-7 mm across. The border consists of a thick made of much 15-20 /< layer up pale brown, branched and which wide. In the central the basal septate hyphae are 3-5 /< part the scale insects becomes with the darker threads almost layer over 50-120 /i high, The threads and fascicles of threads to 1 forming a mat. erect are up mm high. The separate hyphae are dark reddish brown, septate, and very thick-walled, with the cell-wall thick. In the threads coalesce 7-8 n wide, up to 4 n many places to form broad fascicles. Sometimes two smaller fascicles unite 24-27 /t or more near their tips to form one large fascicle. The scale insects are penetrated by large, much the branches of which broad. branched, hyaline haustoria, are 2-3 /< The contains and lesser these also margin numerous probasidia, to a extent are found in the central The part. probasidia are round, pale brown, 15-18 /J. across, with thickened and wide. S slightly cell-wall, with a germ pore 3-4 /< ometimes a new probasidium is formed by proliferation within the old and empty one. The 21 Persoonia Vol. Part 22 i, i, 1959 basidia probasidia develop long, club-shaped, straight measuring 53-65 X6.5-10.5 /(. These are shed and dispersed when still in the one-celled state. Afterwards, the free basidia form cross-walls, becoming 4-celled. Each cell sends out a sterigma which is broad at its base and 1.5—2.5 fx 4-5.5 ft long, bearing one basidiospore. Spore- formation which often is not simultaneous, is brought about in that the whole of each cell protoplasmatic contents passes into the spore. The spores are fabiform with rounded ends, 15-20 X 6-7 /<. Botanical Java, Bogor, Gardens, Sept. 1956 (type), Oct. 1957. On scale insects on the underside of coriaceous leaves, most probably of a Cinnamon species. —free Figs. 1-5. Septobasidium planum Boedijn: 1 —probasidia; 2—germinating probasidia; 3 —various of of unseptated basidia; 4 stages development basidia; 5 —spores. From the above description it is evident that the present species has much in of the Uredinella described Couch. In common with representatives genus as by species of this genus the basidia are also known to break easily off from the pro- basidia which were called teleutospores by Couch. It is on account of these teleuto- and second of that Uredinella spores perhaps a type spores, interpreted as uredospores, was believed to have connections with the Uredinales. Especially the so-called uredospores need commenting here. They germinate from probasidia in the same manner as in ordinary basidia, and are shed as long, non-septate, cylindrical bodies. The comparison, however, with true uredospores does not hold, for, as is well these have the of and known, structures appearance probasidia, on germinating at produce a mycelium. From the description it is once clear that the uredospores BOEDIJN : Septobasidium 23 in Uredinella merely represent young basidia. In addition to the two kinds of spores, the poorly developed sterile tissue in the fructification of Uredinella was thought to be of importance, since in the sori of many of the Uredinales sterile tissue is even resemblance of both the and the of lacking. However, the sterile tissue spores is all establish connection between a superficial nature only, not at adequate to a Uredinella and the rusts. With regard to therelation between Uredinella and Septobasidium, the only difference is in the fact that the fructifications of the former scale grow on a single insect, whereas those of the latter cover whole colonies of the animals. This, however, would sufficient to maintain Uredinella hardly seem as a separate genus. LITERATURE COUCH, N. A intermediate J. 1937. new fungus between the rusts and Septobasidium. In Mycologia 29: 665-673, 30 fig. The 1938. genus Septobasidium. A from In 1941. new Uredinella Ceylon. Mycologia 33: 405-410, 12 fig. The of and S. album. In 1949. taxonomy Septobasidiumpolypodii Mycologia 41: 427-441, 25 fig-.