356 



SCIENCE- G OSSIP 



FRUITING OF LESSER CELANDINE. 

 By Charles E. Bkittox. 



TT has been a long-accepted belief concerning 

 -*- this plant, not in this country alone but also 

 upon the continent of Europe, that there is a vital 

 defect in its sexual organisation of such a character 

 that reproduction in the normal manner of flower- 

 ing plants, by formation of seed, is rare. This 

 sterility, partial or more complete, is accompanied 

 and compensated for by the formation of tubers, 

 a non-sexual means of reproduction which occurs 

 at the underground part of the plant, appearing as 

 thick, fleshy, root-like swellings, or are formed 

 above the soil in the axils of the stem-leaves. The 

 function of the subterranean tubers is essentially 

 to serve as a means of conveying the life of the 

 plant over to the next period of growth ; besides 

 which, however, by the annual increase of tubers, 

 the species is propagated. It is chiefly owing to 

 these root-tubers that the individual plants of 

 Ranunculus ficaria grow in clumps, which are 

 again associated in larger communities. The stem- 

 tubers, from their place of formation in the axils 

 of the leaves, are capable, according to the in- 

 fluence of various agents, of spreading the species 

 into areas in which it may be unrepresented. At' 

 the conclusion of the period of flowering, leaves, 

 stems, and roots disappear, and early in the follow- 

 ing year the tubers give origin to new plants. 



In recent years at least two series of observations 

 have been made upon the lesser celandine — one 

 by Mr. I. H. Burkill, who published in the "Journal 

 of Botany " for 1897 some studies in the " Fertilisa- 

 tion of Spring Flowers on the Yorkshire Coast." 

 As regards the species under consideration, this 

 investigator paid special attention to the number 

 and variety of the insects visiting its flowers, and 

 came to the conclusion that " R. ficaria,, which so 

 extremely rarely sets seed, is an enigma. This 

 failure in seed-production cannot be due to want 

 of fertilisation, for the flowers are visited by a 

 considerable variety of insects, though not very 

 freely/' Professor Federico Delpino also studied 

 the lesser celandine, and came to the rather 

 startling conclusion that our familiar plant is the 

 dwarf functionally female form of the stouter, 

 larger-flowered R. calt/ieaf alius, a Continental plant 

 with a rather restricted range, in this manner 

 accounting for the sterility of the pollen, and the 

 readiness in which the species is propagated 

 asexually. It is no new theoiy that the South 

 European plant just named is, indeed, closely 

 allied to the lesser celandine, and at one time it 

 was expected that it would reward search directed 

 for it in this country. 



Having occasionally encountered R . ficaria bear- 

 ing fruit, I was inclined to regard with suspicion 

 so sweeping a statement that seed-production is a 

 rare phenomenon in this species. In 1898 the 

 opportunity occurred of paying some attention to 

 this question, as on a certain occasion in May 

 abundant fruit was observed in Xorth Middlesex 

 and South Hertfordshire. The amount of seed 

 borne by plants of the lesser celandine in the 

 neighbourhood of Potter's Bar, South Minims. 

 Xorth Mimms, and Shenley was sufficient to dis- 

 pose of the question of the rarity of seed-produc- 

 tion. Daring the same month of May the species 

 was observed fruiting on Great Bookham Common 

 and near Ockham, Surrey. On this occasion the 

 conclusion arrived at was that fruit, if not freely 

 produced, was by no" means rare. In the extreme 

 south-east corner of Surrey abundance of fruit was 

 observed in one locality. From one clump were 

 gathered twelve heads of well-developed fruit and 

 nine heads with undeveloped carpels occurring with 

 the almost mature achenes. After May I failed 

 to observe other instances of seed-production, but 

 during the next year followed up the subject. In 

 late April and early May of 1899 I was at Mid- 

 hurst, in Sussex, and during my walks in the neigh- 

 bourhood noted twelve localities in which R. ficaria 

 was bearing fruit either plentifully or abundantly. 

 In June fruit was being produced at the foot of 

 the downs near Brook, in Kent. During the fir^t 

 fortnight in May, 1900, the species was noticed 

 fruiting well near Westhumble, Westcott on road- 

 side banks. Xew Oxted on dry banks. West 

 Horsley on roadside bank, and abundantly at 

 Chipstead Bottom, all these localities being in the 

 county of Surrey. During the same period the 

 production of fruit was observed in various places 

 in the neighbourhood of Fawkham, Kent. The 

 enumeration of these localities does not exhaust 

 the list of places where the lesser celandine was 

 observed in fruit. It may also be as well to 

 mention that these observations were made during 

 the course of general botanising. 



Seeing that a certain amount of fruit is produced, 

 the question arises as to its origin, bearing in view 

 the alleged sterility of the pollen. Obviously 

 examination of the pollen of R. ficaria is 

 quite as important as observations directed to 

 the frequency of seed-production. The pollen- 

 grains are yellow, spherical, or tetrahedral in a 

 younger state, with densely granular protoplasm. 

 Sometimes a proportion consists of shrivelled, 

 imperfect grains, the percentage of which varies. 



