B A R N E T T E L L A - - A N E W M E M B E R O F

M E L A N C O N I A C E A E

by

DEV RAO

(Department o~ Botany, Vivek Vardhini College) &

P. RAGHUVEER RAO

(Department o/ Botany, Nizam College, Hyderabad-A.P., India)

(with 3 figs.)

(2.IX.X96a)

In this paper a new genus of Melanconiaceae is described, collected by the authors during the study of Hyphomycetes of Hyderabad.

Barnettella speciosa Gen. et. sp. nov.

This fungus was collected growing saprophytically on culms of unidentified grass and leaves of Borassus sp. To the naked eye the fungus appears like a black irregular body on the surface of the substratum which in fact consists of conidial chains. The acervuli are submerged initially and become erumpent subsequently due to the pressure of conidial production. Acervuli are linear-oval to ilTegutar, measuring 300--750 # in length and 200--400# in breadth, consisting of submerged hyphae in the fruiting body. Conidiophores absent and conidia arise directly from the hyphae. Conidia catenate, forming long, simple chains, which are closely adpressed, thus forming columnar conidial chains, resembling a coremium to the naked eye. Conidia dark brown, dictyosporous, consisting of 4--12 rows of cells arranged regularly or irregularly, short cylindrical to oval, 36--60 # long (excluding the separating cells), 21.6--3¢# broad, with obtuse ends, connected by groups of separating cells. The conidial chains measure up to 350 # in length. Separating cells are hyaline to subhyaline, thin and smooth walled, oval to round, a--lO in number, 5--18 # long, 3--8/ , broad, usually arranged in a single row but rarely in two rows.

This fungus is classified in Melanconiaceae, Phaeodictyosporae. Bahusandhika SUBRAM. 4), a simple dematiaceous fungus producing

phaeophragmospores catenately with separating cells has some

5 6 D. RAO & P. R, RAO

resemblance to the fungus under consideration. But the present fungus differs from it in the production of erumpent acervuli, catenate phaeodictyospores with separating cells and the produc- tion of conidia directly from the hyphae. The authors know of no fungus in Melanconiaceae comparable to the described one. Hence, they make the present fungus as the type of a new genus Bar~ettdla, named in honour of Prof. H. L. BARNETT, Department of Plant Pathology, Bacteriology and Entomology, West Virginia University.

Collected on dead culms of unidentified grass from Hyderabad on 14-6-68. "Herb. Hyd". V.V.C.B.L. No. 291.

Barnettella gen. nov.

Pertinet ad Fungos Imperfectos, ad Melanconiaceas, Phaeodic- tyosporas.

Acervuli erumpentes, nigri, irregulares, Hyphae immersae. Conidiophora nulla. Conidia produeta directe hyphis insidentia, fusce brunnea, catenata, e cylinch'icis ovalia, dictyospora; conidia separantur per cellulas nonnullas vel subhyatinas separantes. Conidiorum catenae singulae vel multiplices parallelae.

Barnettella gen. nov.

Fungus Imperfectus, Melanconiaceae, Phaeodictyosporae. Acervuli erumpent, black, irregular with closely grouped and

immersed hyphae. Conidiophores absent. Conidia dark brown, cylindric to oval, catenate, dictyosporous produced directly from the hyphae. Conidial chains simple or columnar. Conidia separated by groups of hyaline separating cells.

Type species:

Barnettella speciosa sp. nov.

Acervuli erumpentes, nigri, irregulares, 300--750 # Iongi, 200-- 400 ,u lati, fusce brunnei vel nigri. Hyphae immersae, conidiophoris nullis. Conidia emergunt directe e hyphis, Iusce brunnea, catenata, cylindrica vel ovalia, dictyospora, 36--60 # tonga, 21.6--34 # lata, apicibus obtusis, efformantia eatenas simplices ad 350 # longas. Conidiorum catenae parallelae vel singulae. Conidia disjuncta per 3--10 celtulas hyalinas vel subhyalinas, ovales vel rotundas, 5--18 # tongas, 3--8 # latas separantes.

Typus lectus in culmis emortnis graminis cuiusdam ad Hyderabad a DEV IRAO, die 15 januarii, anni 1963 et positus in Herbario Hy- derabadense V.V.C.B.L. Sub-numero 291.

Summary Barne t td la - an interesting new fungus of Melanconiaceae-

with B. speciosa as type has been, described, collected as saprophyte on culms of unidentified grass from Hyderabad.

BARNETELLA NOV. GEN, ~7

Barnettella speciosa. (From Type material, "Herb . H yd . " V.V.C.B.L. No. 291)

1. An acervulus. 2. Chain of D~ctyospores with separat ing cells. 3. Columnar conidial chains.

5 8 D. RAO & P. R. RAO

Acknowledgements We wish to express our thanks to Prof. and l~ev. FR. H. SANTAPAU, Chief Bota-

nist, B.S.I., for providing the latin diagnoses, Prof. M. i~. SUXENA, Department of Botany, Osmania University and I)r. S. D. S.kT~VALEKAR, Principal, Vivek Vardhini College for facilities and encouragement.

References I. BAR~TET'r, H. L. (1960). Illustrated Genera of Imperfect Fungi. Burgess Publish-

ing Company. pp. 194--201. 2. CLEMENTS & SHEAR. (I 957). Genera of Fungi. Hafner Publishing Co., New York.

p. 199. 3. SUnRAMANIAN, C. V. (1954). J. Indian bot. Soc. 33(i): 28--35. 4. SUBRAMAZClA~, C. V. (1956). Ibid. 35(4): 467--69.