ON WALLS, ROCKS AND STONY PLACES 



323 



flowers, winch are in small, terminal, tlu-ee-cleft panicles, have very 

 short, blunt sepals ; and much longer, narrow, pointed petals. 



The same order {Crassulacece) includes the House Leek {Semper- 

 vivum teciorum) — a plant 

 which has been introduced 

 into Britain, and is now com- 

 monly seen growing wild on 

 rocks and on the roofs of 

 country houses. Its spread- 

 ing offsets give rise to globular 

 tufts of flowerless shoots, 

 and to thick, succulent, 

 flowering stems that grow to 

 a foot or more in height. The 

 lower leaves are ovate, acute, 

 thick, flesh}% edged with red, 

 and arranged in a dense 

 rosette ; and the flowering 

 stem, with its sessile leaves, 

 is covered with a short, sticky 

 down. The flowers are of a 

 dull pink or purple colour, and 

 are sessile along the spread- 

 ing branches of the stem. 

 They have usually about 

 twelve short sepals ; the same 

 number of pointed petals, 

 t^o or three times the length 

 of the sepals ; about twice as 

 many stamens ; and an ovary 

 of as many carpels as there 

 are petals and sepals. It is 

 interesting to note that half 

 the stamens — those forming 

 the inner whorl — produce no 

 poUen, and that their anthers 

 are often modified into ovaries, the ovules of \A'hich, however, do 

 not mature. This plant flowers in July and August. 



Our last selection from this order is the Wall Pennywort or 

 Navelwort {Cotyledon umbilicus) — a pecuhar plant, common on 

 rocks and walls in the South and West of England. It has a hard 



Y 2 



the london pride or st. patrick's 

 Cabbage. 



