42 



DOMESTIC BOTANY. 



having a narrow mouth like an urn or vase, as in 

 most of the species of Andromeda, and many heaths. 

 In polypetalous flowers the petals vary from linear to 

 nearly round ; they consist of two parts — viz., the claw 

 or lower part, hy which they are attached, and the broad 

 expanded part, called the limb, as for example the 

 pink and wallflower ; but in many cases the distinction 

 between the claw and limb is not very evident. The 

 petals vary from few to many, the prevailing numbers are 

 3, 4, 5, and 6, 5 being the most general (fig. 2, c). When 

 the margins of petals overlap each other the flower is 

 called imbricate, tiled ; when the edges are parallel and 

 touch, even to have the appearance of being united, it 

 is called valvate, like valves. The chief distinctions 

 are as follows : — cruciform, when it consists of four 

 petals placed in the form of a cross, as in the wallflower, 

 ten-week stock, and all the cabbage family ; rosaceous, 

 when of five uniform petals, being spread open like a 

 rose ; this is common to many flowers, even inconspi- 

 cuous ones ; jpajpilionaceous, butterfly-like, in which the 

 petals are of three kinds, the lower edges of the two 

 lowest being loosely united, giving the appearance of a 

 boat and called carina or keel ; above it on each side 

 are two petals, generally spread sideways or standing for- 

 ward, which are called alcB or wings ; above them is the 

 vexillum or standard, which has an upright direction and 

 is usually large and round ; the pea, laburnum (fig. 2, d), 

 furze, and broom are common examples. The corolla 

 varies in size and splendour, from a minute one like that 

 of the chickweed to the magnificent magnolia, cactus, 

 and Victoria lily ; these are even far surpassed by the 

 monstrous flower of Rafflesia Arnoldi (which see). Their 

 texture varies from a thin membrane, as in the generality 



