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The Fern Gazette Volume 18 Part 5

Published 25th June 2009


Edited by M. Gibby & A. Leonard


MAIN ARTICLES

A summary of Indian cheilanthoid ferns and the discovery of Negripteris (Pteridaceae), an Afro-Arabian fern genus new to India
C.R. Fraser-Jenkins & C.S. Dulawat pg(s) 216-229
ABSTRACT
A summary of Indian cheilanthoid ferns treated under nine genera includes three new names, Notholaena dipinnata Fras.-Jenk., Cheilanthes bhutanica Fras.- Jenk. & Wangdi and Cheilanthes tibetica Fras.-Jenk. & Wangdi, and five new combinations, Cheilanthes nitidula Hook. subsp. henryi (Christ) Fras.-Jenk., Aleuritopteris bicolor (Roxb.) Fras.-Jenk. & Dulawat, Aleuritopteris subdimorpha (C.B.Clarke & Baker) Fras.-Jenk. and Notholaena muelleri (Hook.) Fras.-Jenk. Negripteris scioana (Chiov.) Pic.Serm. (Pteridaceae), a close relative of both Aleuritopteris and Chrysochosma, was discovered by the second author in semi-arid conditions in the Kumbhalgarh and Sitamata Reserves of the Aravalli Hills in central Rajasthan, N.W. India, the first record for the Indian sub-continent. It was known previously only from N.E. Africa, Socotra and S. Arabia and is an Afro-Arabian species which, as now found, extends eastwards into the hills of the semi-arid region of W. India.
Checcklist of the ferns and lycophytes of Acre State, Brazil
J. Prado & R.C. Moran pg(s) 230-263
ABSTRACT
One hundred and seventy eight species and five varieties in 24 families and 60 genera of ferns and lycophytes are recorded for state of Acre, Brazil. Data about habit, habitat, material examined, and distribution of each taxon are also presented. Acre contains about one-third of the species of ferns and lycophytes estimated to occur in the Brazilian Amazon region.

Desiccation tolerance in some British ferns
M.C.F. Proctor pg(s) 264-282
ABSTRACT
Leaves of ten British fern species were tested for their tolerance of desiccation. Asplenium ruta-muraria, A. septentrionale, A. trichomanes, A. ceterach, Polypodium cambricum and P. interjectum withstood drying for periods of a week or more to a relative water content (RWC) of c. 4–7%. This is far below the RWC (c. 30%) at which most vascular-plant tissues are irretrievably damaged. One population of Asplenium adiantum-nigrum was desiccation tolerant, another was not. Aspelnium obovatum was fairly tolerant, behaviour differing with intensity of desiccation and in old and young growth. Polypodium cambricum and P. interjectum were both highly tolerant. Polystichum aculeatum was not tolerant. Recovery rates of RWC and the chlorophyll-fluorescence parameter Fv•Fm did not vary greatly between species, with half-recovery times around 2–4 h. The small Asplenium species and A. ceterach dried quickly (halfdrying times a few hours), suggesting little stomatal control over drying. The much slower drying of the Polypodium species suggests that their stomata close under water stress. Photosynthetic electron flow in most species saturated at a quarter to a half of full summer sunlight. Asplenium ruta-muraria, A. septentrionale and A. trichomanes showed a similar tendency to non-saturating electron flow at high irradiances as many desiccation-tolerant bryophytes. In A. ceterach and Polypodium cambricum electron flow was somewhat depressed at high irradiances. The results are discussed in relation to their ecological and evolutionary implications.

The website of the British Pteridological Society