LYCHNIS DIOICA, LINN.

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1 [69] VARIATION IN THE FLOWERS OF LYCHNIS DIOICA, LINN. BY WINIFRED M. CURTIS (With 2 figures in the text) A CONSIDERABLE range of variation in the flowers of Lychnis dioica was observed by Professor T. G. Hill during the summer of Specimens were collected from a hedgerow at Hambledon, Surrey, from two localities, each about one square yard in area, some hundred yards apart. It is possible, therefore, that each group of plants had been derived from the seed of a single parent plant. The variations, which were very conspicuous, involved the colour of the corolla, and the form of the petals, corona, and calyx. The morphology of the flower is typically as follows. There are five petals with erect claws and spreading laminae, 9-11 mm. long, half cleft, the lobes being 3-4 mm. broad, with entire margins. At the junction of lamina and claw are two coronal scales. The calyx is inflated, reddish in colour, hairy, and equal or nearly equal in length to the claws of the petals. In the staminate flower petals and stamens are borne on an androphore, which is terminated by a rudimentary pistil, 2-4 mm. long. The stamens are in two whorls, obdiplostemonous, with swollen bases, which are slightly fused; those of the outer whorl are also adnate to the petals. The inner, antisepalous whorl is the first to elongate and dehisce and is followed by the outer whorl. In the pistillate flowers two whorls of staminodes surround the ovary, which is carried on a short gynophore. These features are constant for the essential organs in all flowers to be described, and are illustrated in Fig. i. One of the most conspicuous variations was in the colour of the petals, which could be classified as mauve, pinkish mauve, white tinged pink, pale pink, pink and deep pink. The form of the petals varied along several distinct lines: the breadth, measured at the base of the lobes, was narrow, less than 5 mm.; medium, 5-7 mm., or wide, more than 7 mm., so that adjacent petals overlapped. Each petal was cleft half way or more deeply, the lobes being approximately in contact or diverging, with margins entire or toothed. Further, the petals were bi-lobed only, or bi-lobed with additional lateral lobes, or with small lateral notches. The toothed corona was

2 70 WINIFRED M. CURTIS in general outline square, bifurcate or asymmetric. Two variations of the square type occurred: in the first the scales bad a narrow base of insertion, and in the second the scales were fused for half their length. The lateral lobes of the corona were either entire or toothed. The calyx could be referred to one of two main types, inflated or cyundric, altbough the calyx of the pistillate flower was more inflated than that of the staminate. In length the calyx was equal, nearly equal or half equal to the claws of the petals. There were differences in the relative sizes of the constituent parts of the flower. Fig. 2 shows some of the variations described. Fig. I. A. Longitudinal section pistillate flower. S, staminode; G, gynophore. B. Longitudinal section staminate flower. A, androphore; P, rudimentary pistil; Si, stamen of inner whorl; S3, stamen of outer whorl. (Diagrams Ards natural size.) These variable characters occurred in a number of different combinations, twenty-five being found in some forty flowers examined, and it is probable that, with little exception, any combination of the variable characters could obtain. The only instance of an association of characters is that of mauve colour, narrow, deeply cleft petals and cylindric calyx. The variation occurred not only in distinct plants but also in flowers of the same plant and, to some extent, in the parts of a single flower. Thus, the terminal flower of a cyme showed narrow toothed petals with distinct lateral lobes, bifurcate corona and inflated calyx, while the second flower of the same cyme had narrow petals, both

3 Variation in the Flowers of Lychnis dioica, Linn. 71 Fig. 2.

4 72 WINIFRED M. CURTIS entire and toothed, some with lateral notches, a square corona and cylindric calyx. \'ariation in the petals of a single flower is illustrated in Fig. 2, 3. Ill several flowers the corona proved to be very unstable. A somewhat similar polj/morphism in the flower of Silene maritima in its natural habitats has been recorded by Salisbury(l) and by Marsden-Jones and Turrillt2). The latter have also reported similar variations in the progeny derived from the seed of a single wild plant. These variations, however, were found always on distinct plants and very probablj', therefore, represent distinct, heritable strains, whereas in the specimens of Lychnis dioica described above there is a far greater range of variability in the same individual. Without cultural experiments it is impossible to distinguish between possibly stable types and fluctuating variations, although it is conceivable that in Lychnis also the floral features may depend on heritable characteristics present in various combinations and expressed phenotypically in varying degrees. In conclusion, I wish to express my thanks to Professor T. G. Hill for his kindness in providing me with the specimens, and for his helpful criticism and advice. REFERENCES (1) SALISBURY, E. J. Polymorphism in the flower of Silene maritima. New Phytol. 10. January' (2) MARSDEN-JONES, E. M. and TURRILL, \\'. B. Researches on Silene maritima and S. vulgarts. Bulletin Miscellaneous Information, Kew, p Fig Flower from above, showing form of petals. 1. Median breadth, margin entire, some lateral notches. 2. Narrow, toothed, lateral lobes. 3. Mixed entire.. 4. Wide and o\ erlapping, deeply cleft, toothed. 5. Wide and overlapping, lobes diverging, entire, (iths normal size.) 6. Medium, deeply cleft, toothed, (jths normal size'.) 7. Narrow, deeply cleft, toothed, lateral notches. 8. Narrow, deeply cleft, lobes diverging, entire. 9. Narrow, deeply cleft, entire and toothed. C 1-5. Types of corona. A' 1-4. Types of calyx. C I. Asymmetric. A'i. Inflated, pistillate flower. C 2. Bifurcate. A' 2. Inflated, staminate flower. C 3. Square, narrow insertion. K 3. Cylindric. C 4. Square, fused half way. A' 4. Cylindric. C 5. Square. (All the figures jv.ths natural size.)

Verwijsnummer rapporterende autoriteit: MDN 5 Reference number reporting authority: MDN 5

Verwijsnummer rapporterende autoriteit: MDN 5 Reference number reporting authority: MDN 5 Medinilla Gaudich. Variety description: NL/MDN/1 1. Reference number of reporting authority Reference number of requesting 2. authority 3. Breeder s reference Medin-8295 4. Applicant Corn.Bak, ASSENDELFT,