A new species of Cronartium from the Himalayas

Abstract

Of the various parasitic rusts of the coniferous trees now under investigation, one which baffled us for many years and has been a serious pest of Pinus longifolia Roxb., the Chir pine, in north and northwestern India, has been recently worked out. The aecidial stage (Fig. 1) which was formerly known as Peridermium orientalis Cooke, and also as Peridermium complanatum var. corticola Barclay, has been recently redescribed as Penidermium himalayense Bagchee (Indian Forest Records, Botany Series, Vol.14, Part 3, 1929). This fungus has caused much mortality every year not only in the plantations of Almora (Fig. 2) and Naini Tal, but has also impeded natural regeneration in Kumaon and Garwhal Himalayas, where the young pine stands appear to be doomed to eventual extermination. The infection and mortality is very severe in young crops of pine up to the advanced sapling stage, but the poles and mature trees are apparently safe from attack. The Cronartium stage has been discovered on Swertia species, of which S. alata Royle, S. angustifolia Ham., S. cordata Wall., appear to be very susceptible to this rust. The biological relationship of the two stages has been proved recently by cross-inoculation experiments. The detailed report of this investigation will appear in a subsequent issue of Indian Forest Records.