Taphrina Osmundae Nishida and Taphrina Higginsii Sp. Nov.

An interesting feature of the genus Taphrina is the high state of development attained on ferns. About twenty species of this genus occur on ferns, seven of them having been described rather recently (2, 3). A few undescribed species are in the writer's possession and it is possible that additional forms may yet be discovered. Although the clavate type of ascus prevails among fern-inhabiting species of Taphrina, as pointed out long ago by Giesenhagen (1), considerable variation in ascus-form exists. There is also marked variation in ascus-size, ranging from Taphrina Hiratsukae Nish. with asci 13-30 / x 4-7 I, stalk-cells 5-8 j X 3-5 p, to T. lutescens Rostr. with asci 27-75 / x 6-11 il (without stalk-cell). Asci with or without stalk-cells are well represented, the former by Taphrina Hiratsukae and other species, the latter by T. filicina Rostr. and at least one undescribed species. Host-lesions vary from inconspicuous, unthickened leaf-spots, as in T. Hiratsukae and other species, to large galls, as in T. californica Mix, or very remarkable outgrowths, as in T. cornu-cervi Giesenhagen and T. laurencia Giesenhagen. All three types of mycelial habit are exemplified by fern-inhabiting species of Taphrina: the subcuticular habit (T. Hiratsukae, etc.), the intercellular habit (T. filicina, etc.), and the habit of growing within the epidermal wall. In fact the wall-habit of mycelial growth, described by the writer for T. amplians Mix and other species (3), is known only in fern-inhabiting species and in two species occurring on Monocotyledons. This paper is concerned with two species of Taphrina which seem to climax the series on ferns if not to form a connecting link between the genera Taphrina and Taphridium.