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SOME OBSERVATIONS ON CYC AS REVOLUTA AND C. CIRC1NALIS GROWING IN LAHORE.*
By Shiv Ram Kashyap,
Professor of Botany, Government College, Lahore.
The observations described in this paper on leaf-clusters and ovules were made on plants of Cycas revoluta and C. circinalis growing in the Government College Botanic Garden and the Lawrence Gardens, Lahore, Some plants were planted in flower pots and were kept constantly under observation. Cycas revoluta is very commonly culti- vated in Lahore gardens but C. circinalis is not so common. The writer has not come across any male plant of Cycas revoluta in Lahore or in its neighbourhood, all the plants being female. It i3 propagated by means of buds which grow on the underground or aerial parts of the stem. These buds when detached and planted grow into new plants which are naturally female. A few years ago the writer obtain- ed some seeds of this species from Japan and these have produced some plants, but the latter have not as yet produced any flowers. Cycas circinalis is represented by many female plants but so far as the writer is aware there is only a single male plant in this locality, growing in a tub in the Lawrence Gardens. The female plants bear buds in fairly large numbers by which the plant is propagated, but the male plant has never produced any bud and therefore it is impossible to increase the number. Only one male cone is produced each year. It is formed during the rains and ripens towards the end of the rainy season, in August. The longest one measured during the last few years was more than eighteen inches, and the thickest, this year 1920, was nearly twelve inches in circumference at the thickest part.
Leaf-clusters of Cycas revoluta. — One series of observations on Cycas revoluta was meant to find out the interval between the suc- cessive leaf-clusters. Coulter and Chamberlain, in the recent (1917) edition of " Morphology of Gymnosperms " state : — " In Cycas revoluta it is said that a crown is formed every other year, but information in regard to the duration of the crowns, as they occur in the field, is scanty and uncertain." The observations recorded in this paper throw light on both these questions. No information about these matters is given in Chamberlain's recent book " The living Cycads."
Seedlings grown from seeds showed what is well-known, that the leaves at first appear singly and later on the number is gradually increased to two, three and more.
• A paper read before the Indian Science Congress at Calcutta. February, 1921.
