THE CYMOSE TYPE. 159 



288. Compound mixed inflorescence is very various and com- 

 mon ; but the combinations have hardly called for special terms, 

 being usually disposed of by a separate mention of the general 

 and of the partial anthotaxy, or that of the main axis of inflo- 

 rescence and that of its ensuing ramification. 1 In Composite, 

 for instance, the flowers are always in true heads, of centripetal 

 evolution. The heads terminate main stems as well as lateral 

 branches, so that they are centrifugal!}- or cymosely disposed. 

 The reverse occurs in all Labiatae and most Scrophulariaceae, 

 where the flowers, when clustered, are in cymes, but these c}-mes 

 are from axils, and develop in centripetal order. It is this 

 arrangement which mainly characterizes the 



THYRSUS. A compound inflorescence of more or less elongated 

 shape, with the primary ramification centripetal or botryose, the 

 secondary or the ultimate centrifugal or cymose. To the defini- 

 tion is generally added, that the middle primary branches are 

 longer than the upper and lower, rendering the whole cluster 

 narrower at top and bottom, and sometimes that it is compact - 

 but these particulars belong only to typical examples, such as 

 the inflorescence of Lilac and Horsechestnut. In the former, the 

 thyrsus is usually compound. A loose thyrsus is a 



MIXED PANICLE. It is seldom that a repeatedly branching 

 inflorescence of the paniculate mode is of one tj-pe in all its 

 successive ramifications. Either the primarily centripetal will 

 become centrifugal in the ultimate divisions, or the primarily 

 centrifugal will by suppression soon run into false botryose 

 forms, into apparent racemose or spicate subdivisions. So that 

 the name Panicle in terminology is generally applied to all such 

 mixed compound inflorescence, as well as to the homogeneously 

 botryose. (278.) 



VERTICILLASTER is a name given to a pair of opposite and 

 sessile or somewhat sessile cymes of a thyrsus or thyrsiform 

 inflorescence, which, when full, seem to make a kind of verticil or 

 whorl around the stem, as in very many Labiatae. The name 

 was originally given to each one of the pair of cymes ; but it is 

 better and more commonly used to denote the whole glomerule 

 or false whorl produced by the seeming confluence of the two 

 clusters into one which surrounds the stem. 



1 Guillaud (in his memoir on Inflorescence, published in Bull. Soc. Bot. 

 France, iv.) proposes to designate as Cymo-Botryes the mixed inflorescence 

 composed of cymes developed in botryose order, ?'. e. the thyrsus ; and 

 Botry- Cymes, the reverse case of racemes, &c., cymosely aggregated. For 

 the former, the old name thyrsus serves appropriately and Avell. 



