ABNORMAL NUMBER OF NEEDLES IN THE
SPURS OF PINUS LONGIFOLIA
S. R. Kashyap
Professor of Botany, Government College, Lahore.
Pinus Longifolia is a common connifer of the outer hills of the Punjab Himalayas and is often cultivated in the plains. The number of leaves in the dwarf shoots in this species is described in the Indian Floras 1 as three. So constant is this number in the adult plant that the writer has not come across a single example of a different number during many years for which the plant has been a subject of study in the Botany classes at the Lahore Government College and in spite of a careful examination of several trees recently. It came as a surprise therefore when, last year, while examining a seedling he came across an abnormality in this respect quite by chance. On examining the seedling further and later on examining more seedlings many such instances were found. On looking up the literature 2 of the subject it was found that the abnormal number of needles in the spurs of many species both in the seedling and the adult plant is by no means rare though no mention of Pinus longifolia has been met with anywhere. Among a pretty large number of species mentioned by Thomson (Botanical Gazette, May, 1914) in this connection, Pinus excelsa is the only Indian species. Again although a number of observations are recorded in the papers mentioned yet the writer has not come across any quantitive study of this subject. This paper records a short study of this kind.
In order to find out the relative frequency of plants with abnor- mal spurs as regards the number of needles and the relative number of different kinds of such spurs on the same plant one hundred and one seedlings were taken from the nursery of the Lawrence Gardens, Lahore, through the courtesy of the Superintendent, and carefully
1 Hooker: Flora of British India; Brandis : Indian Trees, also his Forest Flora ; Parker : Forest Flora of the Punjab, etc. Among other standard books on this subject may be mentioned Elwes and Henry : The Trees of Great Britain and Ireland.
2 Thomson, R. B.: The Spur Shoots of the Pines. Bot. Gazette, May, 1914. Dufrenoy, J. : Pine Needles, Their significance and History. Bot. Gaz., November, 1918. Reference to other literature bearing on this point is given in these papers.