RUDIMENTS OF BOTANY. Xill 



80. The calyx or corolla is said to be labiate or bilabiate, when the sepals 

 or petals are united in one or two parcels. 



81. The papilionaceous corolla consists of five petals; the upper one, 

 usually larger than the others, is called the vexillum or standard ; the two 

 lateral ones, the ales or wings ; and the two lower ones, usually more or 

 less united together by their lower margins, the carina or keel. 



82. When the petal tapers conspicuously towards the base, it is said to be 

 unguiculate. or clawed ; its lower part is called the claw, its upper, the limb. 



83. The dilated apex of the pedicel, from which the floral envelopes and 

 stamens arise, is called the torus or receptacle. 



84. Whatever intervenes between the bracts and the stamens belong to 

 the floral envelopes, and is either calyx or corolla ; of which nature are 

 many of the organs commonly called nectaries. 



85. The manner in which the floral envelopes are arranged before they 

 expand is called their (estivation or prcefloration. 



DISK. 



86. Whatever intervenes between the stamens and pistils receives the gen- 

 eral name of disk. 



87. The disk usually consists of an annular elevation encompassing the 

 base of the ovary ; but it sometimes appears in the form of a glandular lin- 

 ing of the tube of the calyx, as in the Rose; or of tooth-like hypogynous 

 processes, as in the Cruciferse ; or of a fleshy mass, as in Lamium. 



88. The disk sometimes appears to be a mere cellular expansion of the 

 torus, (83) as in Nelumbium. 



89. It is one of the parts commonly called nectary. 



90. The whorl of organs immediately within the petals is composed of 

 oodies called stamens, and they are essential to the production of seed. 



91. When stamens and pistils occur in the same flower it is termed per- 

 fect or hermaphrodite ; but when the stamens are in one flower and the pis- 

 tils in another, the flowers are imperfect or diclinous. 



92. The number of stamens is variable, five or ten being the usual num- 

 ber among the Exogenous, and three to six among the Endogenous plants. 



93. When the stamens do not contract any union with the sides of the 

 calyx, they are hypogynous ; as in Ranunculus. 



94. When they contract adhesion with the side of the calyx, they become 

 perigynnus ; as in Rosa. 



95. If they are united both with the surface of the calyx and of the ovary, 

 they are epigynons ; as in the Umbelliferse. 



96. The stamen consists of a filament and an anther. 



97. Thejilame?it is the body which arises from the torus, and is some- 

 tunes cylindrical, or awl-shaped, or prismatical, and is even at times expan- 

 ded, as if into a scale or petal ; but it is not essential to the stamen. 



98. The filaments are usually free or isolated from each other ; but they 

 are sometimes united into one tube, when they are called monadelphous ; 

 or into two parcels, d'mdelphous ; or into several, polyadelphous. 



