'VRIKSHOPAMA', A NEW GENUS OF STILBACEAE

by

DEV RAO

(Dept. o/ Botany, Vivek Vardhini College, Hyderabad-A.P., India)

&

P. RAGHUVEER RAO

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

(with 5 figs.)

(26.I1.1964)

We propose to describe in this communication a new genus of Stilbaceae, collected during our studies on Hyphomycetes of Hy- rabad.

Vrikshopama swetasakha gen. et. sp. nov.

This fungus was collected growing saprophytically from Nizama- bad, forming dull white to blackish brown irregular colonies on the substratum, extending up to 1--3 cm, consisting of closely aggregat- ed synnemata, decolourising the substratum. Synnematum pale to blackish brown, long-cylindric, measuring 500--800# in length consisting of a basal stalk, which is 180--200 be long and 35--60 # broad. Coremia consist of blackish brown to light brown loosely aggregated hyphae, which are continued, branched, fertile apically, septate, 5--7 be broad, septa are up to 40 # apart. Hyphae become pale to light brown or subhyaline in the apical portion. Conidio- phores are branched ramosely. The distal branches are hyaline to subhyaline, one or more celled, long-cylindric, highly geniculate cutting off conidia acropleurogenously. Distal branches are 18--105t, long and 2--5 # broad, smooth walled producing conidia singly or in groups. Conidia cylindrical, hyaline to subhyaline, smooth walled, one-celled, 3.6--7.2/z tong and 1.5--3 be broad. Young distal branches are geniculate due to growth immediately below a conidial scar and repeated process results in geniculations. When the distal branches are sufficiently old, they show intercalary geniculations. This is due to renewed growth of conidiophores after producing conidia for sometime and again resorting to conidial production.

2 8 8 D. RAO • p. 1~. RAO

This fungus is classified in Fungi Imperfecti, lVloniliales, Phaeostil- baceae, Hyaloamerosporae.

Hans/ordia HlJGHES, Tharoopama SUBRA•. (1956) and Drumopama SUBRAM. (1957) are nearer genera to the above described fungus. Hans/ordia is a simple Dematiaceous form producing amerospores from geniculate sporognous ceils arraenged in false verticills, while

!J ii

Vvikshopama swetasakh~ (from type material V.V,C,B.L. No. 153), 1. Synnema; 2. ]!Zamosely branched conidiophores; 3. Ultimate branches with acropleurogenous conidia; 4. Ultimate branches showing renewed growth and

conidial attachment; 5. Conidia,

Drumopama and Tharoopama are Ptlaestilbaceous. Drumopama pro- duces synnemata witll unbranched, genicutate conidiophores, from which lenticular one-celled, hyaline conidia are cut off acrogenously. In Tharoopama the conidiopllores are unilaterally branched, tile ultimate branches (sporogenous cells) produced in false verticills,

VRIKSHOPAMA, NOV. GEN. 289

cutting off dry, apiculate, globose, one-celled, hyaline conidia. The conidia are acrogenously borne and due to successive production of conidia and renewed growth immediately below the scar of the fallen conidium, give a geniculate appearance to the sporogenous cells. The present fungus, however, cannot be classified in Tharoopama as this differs from it in the production of branches of conidiophores arranged ramosely, cutting off hyaline to subhyaline, cylindrical, amerospores acropleurogenously. We know of no genus in Stilbaceae to take in our fungus and it is, therefore, described as a new genus Vriksho- pama with V. swetasakha as type; the generic and specific names being derived from Sanskrit, Vrikshopama = tree like (indicating the tree like synnema) and swetasakha = white branches (suggest- ing tile hyaline distal branches).

Type material collected on old leaves of Borassus/labelli/er L., from Nizamabad, coll. D. R. on 11--12-- '62 Herbarium hyderabadense V.V.C.B.L. No. 153.

Vrikshopama gen. nov.

Pertinet ad Fungos Imperfectos, ad Moniliales, Stilbaceas, Phae- ostilbaceas, Hyaloamerosporas.

Coloniae cinereae vel pallide nigrae, superficiales, irregulares, con- stantes e synnematibus longo cylindricis, stipitatis, sinplieibus. Sym- nemata constant e hyphis aggregatis, pallide brunneis, septatis, ramosis, laxis in regione apicali fertili. Rami ultimi subhyalini, geniculati, continue vel septati, producentes conidia unicellularia, subhyalina, cylindrica, acropleurogena.

Vrikshopama gen. nov.

Fungi Imperfecti, Moniliales, Stilbaceae, Phaeostilbaceae, Hyalo- amerosporae.

Colonies ash or light brown, irregular, superficiM, consisting of grouped tong-cylindric, stalked synnemata. Hyphae compact, light brown, septate, loosely arranged and branched ramosely, becoming hyaline to subhyaline in the apical fertile region. Tile extreme branches are geniculate, producing conidia acropleurogenously. Conidia hyaline to subhyaline, cylindrical, one or more celled.

Type species:

Vrikshopama swetasakha sp. nov. Coloniae cinereae vel paUide nigrae, superficiales, ad 1--3 cm

longae, irregulares, constantes e synnematibus longis, cylindricis, stipitatis, simplicibus, ad 500--800 # longis. Stipites ad 180--200 # longi et 35---60 ,u lati. Hyphae synnematis compactae, pallide brun- neae, septatae, 5--7 # latae, septis inter se 40 # distantibus, grada- t im evadentes pallidiores, ramosae furcatae et laxae in parte apicali fertili. Rami ultimi vel conidiophori dispositi framosum, producentes conidia. Conidiophori 18--105 # longi, 2--5 # lati, leves geniculati, Mycopathol. et Mycol. App1. XXlII, 4. 19

2 9 0 D. RAO & P. ~. RAO

excidentes conidia cylindrica, subhyalina, 3.6--7.2/~ longa, 1.5--3 # lata, levibus parietibus ornata, continua et acropleurogena.

Typus lectus in foliis siceis Borassi/labelli/eri L., ad Nizamabad a DEV RAO die 11 decembrls anni 1962 et positus in herbaria hydera- badensi V.V.C.B.L. No. i53.

S u m m a r y

In this paper Vrikshopama a new genus of Stilbaceae with V. swetasakha as type is described, which is characterised by the pro- duction of ramosely branched conidiophores, the ultimate branches of which are fertile, cutting off one-celled, subhyaline, cylindrical conidia acropleurogenously.

A c k n o w l e d g e m e n t s

Our sincere thanks are due to Dr. H. SANTAPAU, Director, Botani- cM Survey of India for latin diagnoses, Dr. S. D. SATWALEKAR, Principal, Vivek Vardhini College and Prof. M. R. SUXENA, Dept. of Botany, Osmania University for facility and encouragement. The financial assistance of Vivek Vardhini College Education So- ciety is highly acknowledged.

R e f e r e n c e s

CLEMENTS, F. E. & SHEAR, C. L, (1930) T h e genera of Fungi: 227--31 . Hafne r Publishing Co. New York (1957). HUGHES, S. J. (1951) Studies on Inicro-fungi :IX. Calcarisporium, Verticicladium and Hans/ordia (gen. nov,). Mycol. Pap. 43, 25. SUBRAMANIAN, C. V. (1956) Hyphomyeetes-I. J. Indian bot. Soc. 35 (1): 53--91. SUBgAMA~IAN, C. V. (1957) Hyphomycetes-IV. Proc. Indian Acad. Sci. B. 46 (5): 331--35.