NECTARY. 49 



4. Carxjophyllaceous, like the pink. This corolla consists of 

 five petals, having long claws immersed in a tubular cal}rx. Ex. 

 pink, coclde (Fig. 4). 



5. Papilionaceous, buttei-fly-shaped. Tliis corolla consists of 

 five dissimilar petals, wliich have received names as follows ; — 

 the upper and largest is called the banner {vexilluni); the two 

 lateral ones beneath this, the; zym^5 (a/<«); and the two lov/er 

 ones cohering by their lower margins, the keel {carina). Exam- 

 ples, pea, bean, locust. Plants with this kind of corolla consti 

 tute the greater part of the Leguminosa?, one of the most 

 extensive and useful of the natural famiUes. 



106. Physiological structure. The floral envelopes are 

 .found, in then- physical organization, to agree with leaves, of 



which they are only modifications. They consist of thui expan- 

 sions of cellular tissue, traversed by veins of dehcate spiral 

 vessels, all covered with an epidermis often having stomata. 

 Their various colors arfe produced by secretions contamed in the 

 little bladders of the cellidar tissue. 



§ 7. OF THE NECTARY AND DISK. 



107. These are terms which have been appHed to certain 

 anomalous forms of the floral organs, and are veiy variable La 

 structure and position. 



a. The NECTARY {nectcir, honey) is properly an apparatus for the secretion of 

 honey. In tbe violet, larkspur, columhine, &c., it consists of a prolongation of 

 the petal into a spur. In the nasturtium it is a similar prolongation of the sepal. 

 In the passion flower, grass paniassus, gold-thread, &c., the nectaries are merely 

 abortive stamens passing into petals. ' In the lady's slipper and other Orchida- 

 ceous plants, the lower petal being inflated and larger than the rest of them, was 

 called nectary by the Linnean school, but by modern ■«Titei"s the labellum, or 

 lip.: 



b. Tlie DISK, is a teiTu applied to certain little projections situated between the 

 bases of the stamens and the pistils. ■ Its more common fonn is that of a raised 

 rim, either entire or variously lobed, surrounding the base of the ovary, that is, 

 hypogynous [ZttZ, under, yviii, the pistil), as in the peony, or it appears at the top 

 of the ovary when the calyx is superior, and is then said to be epigynous {fTrt, 

 upon, yvvn), as in the Comus. 



c. The true character of the disk is little understood. It is supposed by 

 Lindley to consist of stamens in a rudimentary state, as it is sometimes separated 

 into a circle of glandular bodies, alternating mth the true stamens. 



