CANADIAN EANUNCULACE^. 17 



doubtful raulc, or whose relations to other reputed species are still imperfectly under- 

 stood, or whose range has not been fully traced. 



The Ranimculaceœ^ form a large natural order of flowering plants, distributed chiefly 

 throughout the temperate and cooler parts of the northei'n hemisphere. They belong to 

 the polypetalous division of Dicotylédones, and form the first order of Bentham and 

 Hooker's " Genera Plantarum," as of most other modern systematic woi-ks. In .Tiissien's 

 " Grenera Plantarum," they formed the first order of " Class 13, Polypetalous Dicoty- 

 ledonous plants, with hypogynous stamens." Upwards of 1,200 species have been 

 described by authors as inhabiting the globe, only a small proportion being Australian, 

 but Hooker and Bentham reduce the number of well-distinguished species to 540. Lindley 

 had estimated them at 1,000. 



Whilst, in regard to structure, the boundaries of the order are pretty well defined, 

 and the plants which it <;ontains present a certain viniformity in the form, modes of 

 division and incision of the leaves, which, in a large majority of the herbaceous species 

 are more or less tripartitely or palmately divided, and always without stipules, although 

 often with flattened petioles, yet the several genera present considerable diversity of 

 modification in the form, number, and arrangement of the parts of the flower. In the 

 genus Clematis, the calyx consists of large petaloid sepals, whilst the petals are mostly 

 absent. In Anemone we have the same modifications, with this difierence, that the sepals 

 are imbricate in œstivation, that is, overlapping, and not valvate or meeting at the 

 edges on the same plane. In Thalielriim, the sepals are small and imperfectly petaloid, the 

 stamens in some of the species forming the conspicuous part of the flower. In Ranunculus, 

 the calyx consists of five green imbricate sepals, assuming the more usual general 

 form, texture and colour of this organ as seen in other families of plants, whilst, in this 

 genus, the corolla also assumes its more normal form as a verticil of large, flat or cupped, 

 bright-coloured petals. Myosurus presents us with other modifications ; the sepals are 

 spurred, the petals are saccate and stalked, and the receptacle is greatly elongated. Caltha 

 has large petaloid sepals, but no petals. In TroUius, the sepals are also large and 

 conspicuous, variable in number, but there are slender petals with a pit at base. In 

 Coptis the petals are shortly tubular at the apex. In Aquilegia they are funnel-shaped, 

 being narrowed posteriorly into long hollow "spurs." Then there are two genera in 

 which the flower is irregular, viz.. Delphinium and Aconit.iim. In these, as well as 

 in some others, the petals are peculiar, small, deformed, or altogether absent. The 

 fruit also varies considerably in this order. In most cases it consists of a large num- 

 ber of minute nut-like achenes (each containing a single seed) ; but in Pœonia, Caltha, 

 TroUius, Coptis, Aquilegia, Delphinium-, Aconitum, the fruit consists of several or many-seeded 

 " follicles " or pods. In Actœa, etc., it is a berry. 



Many of these plants have powerful physiological actions, owing to organic 

 compounds which they contain; several have been long in use in medicine, and as 



1 Ranunculacex. A. Laurent Jussieu, Genera Plantarum (1789) ; A. P. De Candolle, Reg. Veg. Syst. Nat. (1818) ; 

 Lindley, Veg. Kingdom (1853) ; Endliclier; A. Gray; Bentham & J. D. Hooker (1862). 



Sec. IV., 1884. 3. 



