THE MORPHOLOGY AND CYTOLOGY OF SPOROGENESIS OF TRICHOMANES PROLIFERUM BL.

Abstract

Summary The morphology of Trichomanes proliferum is described and the anatomy of the petiole and rhizome is discussed in relation to the habitat of the plant and its growth. It is suggested that after the initial phases each frond may be regarded as a more or less independent colony of cells, the complexity ultimately attained by the frond depending upon the supply of primary metabolites reaching it directly from without. It is reported that in the plant collected from Gunong Poe the chromosomes failed to pair at meiosis and 108 univalents were present. A means is suggested by which polyploidy could have arisen frequently in the Hymenophyllaceae.

Reticulate evolution in the Crepidomanes minutum species complex (Hymenophyllaceae)

“…These would display intermediate morphologies that could not be easily assigned to one species or another. Evidence for apogamous reproduction following the Braithwaite system ( Braithwaite, 1964 ;Walker, 1985 ) in the complex has been reported in specimens from multiple localities representing at least two cytotypes, including India ( n = 108; Mehra and Singh, 1957 ), Malaysia ( n = 108; Bell, 1960 ), the Solomon Islands ( n = 72; Braithwaite, 1969 ), and New Hebrides ( n = 108; Braithwaite, 1975 ). Makiling, Philippines, displayed a great diversity of morphologies with many intermediate forms and was unable to distinguish any separate species (although he attributed this to phenotypic plasticity rather than genetic variation).…”

The branching of Trichomanes proliferum (Hymenophyllaceae)

“…These buds are quite different from those of bulbils, suckers, etc., in that they do not lead to the formation of new autonomous plants, but appear to contribute to leaf proliferation. Bell (1960) and Bierhorst (1974) described stolons produced by epiphyllous buds in their specimens. These epiphyllous buds appear unusual in extant ferns and characterize some proliferating species of the section Gonocormus, including T. proliferum (Morton 1968).…”

“…1 and 2). Bell (1960) described the biology of T. proliferum (from Sarawak, Malaya) and demonstrated the relationship between the morphology, anatomy, and ecology of this plant. The whole plant was interpreted as being composed of a collection of independent colonies, each formed by a system of proliferating leaves.…”

The Cytology and Derivation of a Temperature‐sensitive Meiotic Mutant in the Fern Ceratopteris

“…Root tip somatic counts by Ghatak (1964) showed the expected sporophytic numbers of 2n = 42 for H. exsertum and 2n = 72 for T. late-alatum. Bell (1960) reported similar behavior in T. proliierum and suggested that this taxon and T. insigne forma B were possibly apomictic in nature. He suggested that the two species from the populations in India may be isolated cytotypes.…”