388 A TEXT-BOOK OF BOTANY. 



corollas — one, as in lavender, where the mouth of the tube Is open^ 

 known as ringent ; and another, where the mouth is closed, as in 

 Linaria, called personate. 



There are a number of other special forms of calyx and corolla, 

 particularly the latter, and of these may be mentioned the follow- 

 ing : A corolla, like that of the harebell, which is more or less bell- 

 shaped, is termed caaipanulate; a more or less campanulate 

 corolla contracted near the opening, as in Gaultheria, is spoken 

 of as urceolate or urn-shaped ; in the morning glory and other 

 Convolvulacese the corolla is said to be infuxdibuliform or 

 funnel-shaped ; a corolla in which the limb spreads abruptly from 

 the tube, as in Phlox and coffee, is termed hypocrateriforai 

 or salver-shaped ; a corolla with a short tube and outspreading 

 limb, as in potato, is said to be rotate or wheel-shaped ; a rotate 

 corolla with the margin more or less upturned is called crater i- 

 FORM or saucer-shaped ; in aconite the upper petal is hood- or hel- 

 met-shaped, and the corolla is spoken of as galeate ; in the violets 

 one of the petals has a spurred appendage and the corolla is de- 

 scribed as saccate or calcarate, while the modified petal in the 

 orchids is known as the labellum. 



Duration of Calyx and Corolla. — There is considerable 

 difference in the length of time that the calyx and corolla persist, 

 not only with reference to each other but in different plants. The 

 parts are said to be caducous when they drop from the flower as 

 soon as it opens, as the calyx of the poppy ; when they remain for 

 a day or so, they are said to be ephemeral or fugacious, as in 

 the petals of the poppy ; in the rose and apple the petals fall away 

 soon after the pollen reaches the stigma and they are said to be 

 DECIDUOUS ; in some flowers the petals wither but persist until the 

 maturing of the fruit, as in the Droseraceae, and are known as 

 MARCESCENT ; the calyx may remain unaffected until the maturing 

 of the fruit, as in the Labiatae, when it is said to be persistent. 



Bracts. — In addition to the floral envelopes, other more or 

 less modified leaves are borne on the flower branch below the 

 flower, frequently at the base of the flower stalk, and these have 

 received the name bracts. The bracts closely resemble the foli- 

 age leaves, but usually are smaller and frequently are mere scales, 

 without chlorophyll. In some cases, however^ they are large and 



