574 



BOTANY 



IMPORTANT UKXKUA. Many of our commonest meadow and woodland plant* 

 belong to this order. They are all in greater or less degree poisonous. Numer- 

 ous species of Ranunculus, characterised by the usually yellow flowers, convex 

 receptacle, and fruit composed of numerous free achenes, occur in Britain. The 

 petals have a nectary at the base. Leaves palmately divided more or less deeply. 

 R. sceleratus is very poisonous (Fig. 590). R. arvensis with large, spiny achenes 

 or nutlets (Fig. 589). The aquatic species of Ranunculus, belonging to the section 



Fi<;. 



S. Flowci- of Jiunttncitluj! scderatus ; It, tlic sanir. cut tliroujjli longitudinally ; 

 (After BAILLON.) 



Jiatrachium, are often heterophyllous (Fig. 35, p. 34), the floating leaves serving 

 to support the flowers above the surface of the water. 



Species of Anemone are also widely distributed in Europe. A. nemorosa 

 occurs commonly in woods and is one of our early spring flowers. It has a 

 horizontal, subterranean rhizome, which terminates in a flower, the further growth 

 of the plant being carried on by a lateral shoot. Perianth simple, petaloid. All 

 species of Anemone have at a greater or less distance from the perianth a whorl 

 of, usually, three leaves forming an involucre (Fig. 

 591). In A. hepatica this stands just below the 

 perianth and thus resembles a calyx. All the species 

 are to some extent poisonous, especially A. Pulsatilla. 

 Many are valued and are cultivated in quantity 

 during winter, especially on the Riviera, to supply 

 the market with cut flowers. The plants of the genus 

 Clematis are mostly woody and differ from other 

 Ranunculaceae in having opposite leaves. Many 

 species are cultivated. C. vitalba is one of our few 

 native lianes. The achenes of the species of Clematis 

 and of man y kinds of A mone a provided with hairy 

 or leathery appendages, which facilitate their distribu- 

 tion by the wind. The floral axis in the Mouse-tail 

 (Myosurus) is greatly elongated and the spiral arrange- 



ment of the small achenes upon it is very evident. Thalictrum has large, showy 

 stamens, and the perianth is readily shed (on apogamy in this genus, cf. p. 518). 

 Calthti palustris, the Marsh Marigold (Fig. 592), is one of the most conspicu- 

 ous spring flowers in damp meadows. Perianth simple, bright yellow. Leaves cordate 

 or reuiform, short-stalked, with erect sheathing base. Fruit composed of follicles. 

 ffeUeborus foetidus (Fig. 593) has firm, palmately divided leaves. The prominent 

 inflorescence bears in January or February greenish flowers which stand in the 

 axils of the broadly sheathing, three-toothed bracts and are spirally constructed 

 throughout. The five large sepals persist until the fruit is ripe. The petals, 



Fii;. .W.i. llanunculus aw ,"(.-. 

 Carpel in longitudinal section. 

 (After HAILLON, enlarge'!.) 



