180 TBINIDAD AND TOBAGO BULLETIN. [XVIII 4. 



ROSELLINIA PEPO., Pat. 



This species was originally described by Fatouillard in 1908 from 

 material on the bark of Hymenaea Courbaril collected by Duss in 

 Guadeloupe. In the British Antilles the perithecia have been collected 

 in Dominica, St. Lucia, and Grenada. From the published accounts of 

 root diseases in Jamaica, Porto Rico and Martinique it seems probable 

 that the species also occurs in those islands. 



Its most general importance is due to its attacks on cacao, but it is 

 capable of producing destructive effects on any of the ordinary crop 

 plants, herbaceous or woody, which are planted on land recently cleared 

 from forest. Under such circumstances, limes in Dominica have 

 suffered severely from this species, as well as from E. hunodea. 



Where cacao trees have been killed by the fungus and other plants 

 have been put in for temporary fillers, I have seen dasheens, bananas, 

 pigeon pea, cassava, and horse bean all attacked. Sugar cane has 

 several times been seen to survive, but I cannot say that it is really 

 immune. Barber includes it in his list of plants affected. 



Patouillard's description of the fungus is as follows (trans.) : — 

 Perithecia scattered or in groups, situated on the crustaceous 

 conidia-bearing subicle, globose, somewhat stalked, '2.5 to 3 

 millimetres in diameter, dark brown carbonaceous, furnished 

 with a conical shiny black osteole, remaining closed, 

 surrounded by a darker somewhat more flattened areole ; 

 asci elongate, capitate at the apex, furnished with an ovoid 

 pore, turning blue with iodine, much attenuated below, eight- 

 spored, 10 to 12 microns in breadth ; paraphyses numerous 

 linear ; spores brown, straight, fusiform, pointed at each end, 

 measuring 62 to 67 by 8 to 9 microns, at first increased at 

 each end by a glassy halo, later bare. 

 There are present erect conidiophores (Graphium) 1 to 3 mm. in 

 length, 30 to 60 microns broad composed of brown septate 

 hyphae 4 to 6 microns thick, situated on the crustaceous 

 subicle. Conidia not seen. 



The perithecia are borne, usually at the base of the stem, amongst 

 and in succession to the conidial fructifications, on the somewhat 

 carbonaceous layer which is formed on and in bark which has become 

 thoroughly infested. 



The perithecia are formed much less freely than in the case of 

 i?. bunocles, and in spite of long-continued search, material containing 

 ripe asci has only once been obtained in the British islands : this was 

 found by the writer on a dead lime tree in Dominica, in a situation 

 with an annual rainfall of some 250 inches. Examination of this 

 material at Kew enabled Miss E. M. Wakefield to identify the fungus as 

 Patouillard's species. 



The perithecia are normally slightly verrucose (Fig. 1) but are 

 sometimes found smooth. Apparently this is due to weathei'ing, 

 though possibly (cp. B. hnnodes) there is some variation in the amount 

 of roughness developed. 



