80 
INFLOKESCENCE. 
are on different trees ; and of the order Octandria, because its 
barren flowers have eight stamens. 
The Spadix is an assemblage of flowers growing npon a com 
mon axis, and surrounded bj a spatha or sheath. 
Fig. 96. 
Fig. 96, A, «, represents the blossom of the wild tur- 
nip {arum) ; a, the spatha, which is erect, sheathing, ob- 
long, convolute at the base, and compressed above and 
below the middle, b; c represents the spadix, which, 
from its club-shaped appearance, is called clavi-form 
(from clava, a club). 
At B is the spadix divested of the spatha ; a is the 
clavi-form summit ; 6, a ring of filaments without an- 
thers ; c, a ring of sessile anthers ; d, a dense ring of pis- 
tillate flowers with sessile stigmas ; each ovary produces 
a one-celled globular berry. This plant is of the class 
Moncecia, because its staminate and pistillate flowers are separate, but yet grow on 
the same plant ; it is in the order Polyandria, because its stamens are numerous. 
a. The jloral axis sometimes assumes a leaf-like 
or phylloid appearance (from ph^llon, a leaf, and 
eidos, form), as in Xylophylla, Fig. 97, a, where 
the clusters of flowers are developed in a centrif- 
ugal or cymose manner ; sometimes a flattened 
peduncle composed of adhesions of several pe- 
duncles, forms a crested summit covered with 
pointed bracts, and supporting flowers as in the 
cockscomb (Celosia, Fig. 97,6); in the Vallisneria, 
spiralis (Fig. 97, c), the flowers standing on spiral 
peduncles are by their uncoiling raised to the 
surface of the water previous to their becoming 
fertilized. The different kinds of inflorescence 
are chiefly determined by the elongation or short- 
ening of the axis, and the presence or absence of 
pedicels or stalks to the flowers. Thus, a spike is 
a raceme in which the flowers are not stalked ; 
the umbel is a raceme in which the primary axis is 
shortened ; the head is a spike in which the same 
shortening has taken place. The centrifugal and 
centripetal modes of inflorescence are sometimes 
combined in the same plant ; in some compound 
flowers the heads of flowers taken as a whole are developed centri fug ally, the ter- 
minal head first ; while the florets, or small flowers on the receptacle, open cen- 
tripetolly, those of the cu-cumference first. 
85. The RECEPTACLE is the termination of the floral axis, the 
summit of the peduncle upon which the flowers expand; it is 
not in reality a proper organ, though from the importance of 
this point of the stem it is spoken of as such. The summit of 
the peduncle is usually somewhat enlarged, to allow the develop- 
ment of the envelopes. When it forms a fleshy ring surround- 
ing the base of the carpels, as in the orange, it is called a dish. 
The receptacle is also called the clinanthe (from Idine., bed, and 
antJios^ flower), and sometimes the torus (from the Latin, signify- 
ing bed). In simple flowers, as the tulip, the receptacle is scarce- 
Spadix— Various appearances of the floral axis —85. What is the receptacl* t— Diflerent names ol 
tlie receptacle. 
