THE FLOWERS AND FRUIT. 23 



bracteas. Properly speaking, this is not a calyx, but an Invo- 

 lucre of a particular kind, investing an expanded receptacle, on 

 which are placed numerous small flowers. It is 



Simple, when the flowers are surrounded by a single row of 

 leaves. 



Double, when the flowers are surrounded by two rows of 

 leaves. 



Equal, when in a simple calyx of this kind the leaves are all 

 of equal length. 



Imbricated (Fig. 113, 114.), when the common calyx consists 

 of numerous imbricated leaves or scales, one lying close above 

 another. 



Spherical, Globose, or Globular (Fig. 113.), when it has the 

 form of a sphere or balL 



Hemispherical (Fig. 114.), when round below and flat 

 above. 



Egg-shaped, when of the form of an egg. 



Cylindrical, when long and round. 



Flat, when the scales are spread out. 



The scales or leaves of the common calyx are described in the 

 same manner as leaves. Thus they may be egg-shaped, lance - 

 shaped, fringed, thorny or spinous, &c* 



3. The Scales of the Catkin (Fig. 105.) are considered as 

 bracteas, analogous to leaves of a calyx. (Fig. 115.) 



4. The Outer Husk or Chaff-scale (Fig. 116.) is what may 

 be considered the peculiar calyx of grasses, and plants allied to 

 them. It may be single, of one piece or scale ; of two, three, 

 or more pieces. It may be egg-shaped, lance-shaped, keeled, 

 acute, &c. 



II. Of the Corolla. 



The Corolla or Blossom is the envelope of coloured and 

 delicate leaves, always internal with respect to the calyx, and 

 s-urrounding the stamens and other essential parts. The leaves 

 or pieces of which it is composed are called Petals. When it 

 appears to consist of one piece only, it is called Monopetalous, 

 or in common language a corolla of one petal. Corollas are 

 seen in Fig. 87 a, 109 a, 110 b. 



The corolla of grasses consists of one or two pieces called 

 husks or glumes (Fig. 116, b, b.), resembling the chaff-scales. 

 There is frequently appended to them a hard elongated body 

 called the awn (Fig. 96.), which is often twisted. 



