78 



INFLOKESCENCE. 



Fig. 92. 



the flower. Fig. 91 (Lamium, of the family Labiatse) repre- 

 sents a verticillaster, or whorl. A circle of flowers j^roduced 

 at the axils of leaves, was formerly termed a whorl ; but as the 

 central flowers are found to expand first, or to be centrifugal, 

 this mode of inflorescence is now considered as cymose^ the 

 flowers being sessile, or nearly so, and the clusters are called 

 veiiicillasters. Yet as the term whorl or whorled has been by 

 former botanists used in descriptions of plants, we shall retain 

 the same in its usual acceptation. 



Raceme (Fig. 92, o) consists of numerous 

 flowers or pedicels, and all arranged on one 

 common peduncle, as in the locust and currant. 

 The only diflerence between a raceme and a 

 spike is, that in the latter the flowers are more 

 densely inclosed with very short pedicels or none. 



Panicle (Fig. 92, IS) bears flower-branches 

 in the place of simple flowers. In this case the 

 secondary floral axis, or racMs^ gives rise to 

 tertiary ones, as in some of the grasses and the 

 oat. If the peduncles in the middle of a dense panicle are 

 longer than those at the extremities, a thyrse is produced, as 

 the lilac and grape, where the panicle is contracted into a 

 somewhat ovate form. 



Sjnhe (Fig. 93, a) is an assemblage of 

 flowers arising from the sides of a common 

 stem ; the flowers are sessile, or with very 

 short peduncles, as some of the grasses and 

 mullein. A spike is generally erect. The 

 lowest flowers usually blossom and fade be- 

 fore the upper ones expand, or the expansion 

 is from base to apex. When the flowers in 

 a spike are crowded very close, an ear is 

 formed, as in Indian corn. 



Tlnibel (Fig. 93, J) consists of several flow- 

 er-stalks, of nearly equal length, spreading out from a common 

 center, like the rays of an umbrella, bearing flowers on their 

 summits, as in the carrot. K the secondary axes or rays arise 

 from the primary ones in the same manner, a compound umbel 

 is formed, as in the parsnip. A compoimd umbel bears the 

 same relation to a panicle that a simple umbel does to a raceme. 



Cyme (Fig. 93, c) resembles an umbel in having its common 

 stalks all spring from one center, but difl'ers from it in having 

 those stalks irregularly subdivided ; as the snowball and elder. 

 The order of development of these flowers is centrifugal. A 

 cyme reduced to a few flowers, is caUed a "oerticillaster / crowd- 



Fig. 93. 



Raceme — Panicle — b^pikc— Umbel — Cynxe. 



