Cylchgronau Cymru

Chwiliwch trwy dros 450 o deitlau a 1.2 miliwn o dudalennau

The length of Rhizome internodes varied within and between rhizomes and plants. The following mean lengths have been recorded from 3 clones in the Cwmdare area 22.85 ± 2.45 mms, 16.20 ± 0.58 mms., and 15.33 ± 0.59 mms.; having an overall average of 16.61 mms per internode for 185 measurements. A germination test was carried out on a small amount of seed and showed a high percentage of polyembryony, a feature very common in Poa pratensis (Akerberg 1942) and illustrated below for transplants (100 seeds) and wild plants (200 seeds). No. seeds Seedlings/seed Polyembryony Germination. 1 2 3 4 100 66 15 7 2 24 90 200 132 18 1 9.5 75.5 It is of interest to note that several fungi have been recorded on the foliage, namely Puccinia poarum, Uromyces poae and Erysiphe graminis, whilst Ergot (Claviceps purpurea) was found on several plants from Craig-y-Llyn, N. Glamorgan. From the field work already carried out it is clear that sub- caerulea is very common in the hill country of South Wales, being found in a wide range of habitats but being characteristic of grass- lands on which stock concentration and agricultural activities are high. The floral morphology of the subspecies is remarkably uniform and the comparatively small panicles are readily recognised. The sterile tillers are broad-leaved, and although leaf length is variable in some populations, plants are normally short-leaved under field conditions. However, a fuller evaluation of all charac- ters depends upon detailed transplant studies. In conclusion I should like to thank the Director, Royal Botanic Gardens, for the identification of some specimens, and Dr. A. Melderis, Science Museum (Natural History) for his opinion of some of the plants. REFERENCES Akerberg, E. (1942). Hereditas 28, 1-126 Gustaffson, A. (1947). Acta Univ. Lund., 43, No. 12, 183-370. Hubbard, G. E. (1954). Grasses: Penguin Books. HYDE H. A. and WADE, A. E. (1934). Welsh Flowering Plants. LovE, A. (1952). Hereditas, 38, 11-32. Melderis, A. (1955). Species Studies in the British Flora. Bot Soc., B.I., Symp. 3 140-159. Tutin, T. G. (1952). Flora of the British Isles.