58 



AGGREGATE FLOWERS, 



many florets placed on a receptacle, on fastigiate peduncles* 

 that are all produced from the same point. A simple umbel is 

 when the receptacle is but once divided into peduncles ;...a com- 

 pound umbel is when all the common peduncles are subdivided 

 into umbellulm, little innbels an umbellula therefore is a partial 

 umbel. 



Umbellate flowers, properly so called-]-, have the following pro- 

 perties : 1. A common receptacle divided into peduncles in the 

 manner above-mentioned, whether the umbel produced be plane, 

 fiat; convex, rounding; or concave, hollow. 2. A germen under 

 the corollula. 3. Five distinct stamina that are deciduous. 4. 

 A bifid pistillum. 5. Two seeds joined at their summits. 



A radiate umbel is when the marginal petals are larger than 

 those of the disk, as in Tordylium, CaucaLis, Coriandrum, Am- 

 mi., and some species of Heracleum ; an umbel may vary also 

 in having the flowers of the margin differing in sex from those 

 of the disk, as in Astrantia, Caucalis, Artedia, GEnanthe, and 

 Scandix. The involucrum varies, in being either tetr aphyllous, of 

 four leaves, as in Hydrocotyle, Sison, and Cuminum ;...penta~ 

 phyllous, of five, as in Bupleurum, Scandix, and Eubon ; ...hep- 

 taphyllous-, of seven, as in Ligusticum decaphyllous, of ten, as 

 in Artedia :...with the partial involucrum dimidiate, halved, going 

 but half round, as in iETHUSA, Coriandrum, and Sanicula 

 or caducous, falling off, as in Ferula and Heracleum. 



4. A Cymose flower is an aggregate one, of many florets, 

 placed on a receptacle upon fastigiate % peduncles, the primary 

 6nes of which issue from the same centre, as in an umbel ; but 

 the secondary, or partial ones, lie dispersed without order; 

 which circumstance distinguishes the cyma from the umbel, as 

 in Opulus, Ophiorrhiza, and the species of cornus, called Vir- 

 ga-sanguinea, or bloody-rod. 



* See the first note in Chap. VIII. 



■f The umbellate flowers, properly so called, belong to the order Digynia, of 

 the class Pentaudria, See Part II. Chap. VIII. 

 X See the first note on Chap. VIII. 



