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ELEMENTS OF BOTANY. xiii 
:49. When the flowers arise from the axil of the ordinary leaves of the stem, 
they are said to be axillary; but oftener, they are disposed in a more or less 
obvious cluster, each arising from the axil of a greatly reduced leaf, or Bract. 
50. The stalk of a solitary flower, or of a cluster of flowers, is termed the 
Peduncle; or, when it proceeds from the root, a Scape; and that of each indi- 
vidual of a cluster is called a Pedicel The main axis of a cluster, or that 
portion of the common peduncle which bears the flowers, is called the Rachis. 
51. The indefinite inflorescence includes the Spike, Ament, Spadix, Raceme, 
Corymb, Umbel, Head, and Panicle; the definite, the Cyme and its modifications. 
52. The Spike consists of a more or less elongated rachis, with the flowers 
sessile, or nearly so, in the axils of the bracts. 
53. The Ament, or Catkin, is the scaly deciduous spike of the Pine and 
Willow. 
54. The Spadix is a spike with the flowers borne on a thick and fleshy rachis. 
It is naked, as in the Golden-club, or enclosed in a hood, called the Spathe, as in 
the Indian Turnip. 
55. The Raceme presents the elongated rachis of the spike, but the flowers 
are raised on pedicels. 
56. The Corymb is a short raceme, with the lower pedicels elongated, so as to 
bring their flowers to the same level as the upper ones. 
57. The Umbel is a modification of the raceme, but with the rachis so much 
` contracted, that the pedicels (rays) apparently spring from & common contre. 
When the umbel is compound, the partial umbels are termed Umbdlts. — 
58. A Head is an umbel with sessile flowers. - "The crowded rir of dis and 
the preceding are collectively termed the Znvolucre, and those of the umbellets, 
the Znvolucel. 
59. When the pedicels of a raceme or corymb are transformed into branches, 
either simple or successively divided, the inflorescence becomes a Panicle. 
60. When the further growth of the axis is arrested by a single terminal 
flower, and from the axils below branches are developed, each terminated by a 
flower, and bearing branches in the same manner, the inflorescence is said to be 
cymose or centrifugal. But it presents several peculiar forms, occasioned either 
. by the imperfect development, or by the entire suppression of some of its parts. 
Some, as the true Cyme, are short and expanded ; others are elongated, like the 
spike or raceme. In all, the flowers expand successively from the summit, 
downward, or from the centre, outward. 
61. The Flower consists, commonly, of one or more whorls of leaves, called 
the Floral Envelopes, — of which the outer one is termed the Calyz, and the inner. 
one the Corolla, — an inner whorl of thread-like organs, called the Stamens, and 
one or more central organs, called the Pistils. These are inserted on the apex 
of the axis, which here takes the name of Torus, or Receptacle. ` 
62. The Floral Envelopes are sometimes wanting ; but the stamens and pis- 
pter eyes pape ipli. = aii ae ee Ful 
