THALAMIFLORjE. 



221 



Character. 



Thalamus flat or rounded. Calyx : sepals 5, rarely 3 or 4, more 

 or less united below, valvate in the bud, often surrounded by an 

 epicalyx. Corolla: petals equal in number to the sepals, hypo- 

 gynous, contorted in aestivation, free or adherent to the tube of 

 the stamens. Stamens indefinite, monadelphous, hypogynous, all 

 perfect ; anthers 1 2-celled. Ovary : carpels several, each form- 

 ing a cell around a central axis, either coherent into a multilocu- 

 lar compound ovary, or distinct ; ovules definite or indefinite, on 

 the ventral suture ; styles equal in number to the carpels or twice 

 as many ; coherent or distinct ; stigmas various. Fruit : a several- 

 celled capsule, or a collection of separating indehiscent cocci or 

 of follicles, the carpels 1- or many seeded ; seeds with little or no 

 perisperm, embryo curved, cotyledons much twisted, oily, testa 

 sometimes hairy. 



ILLUSTRATIVE GENERA. 



A. Andrcecium tubular ; tube entire 

 or but slightly divided at the apex. 



Tribe 1. MALTESE. Herbs or un- 

 der shrubs, Staminal column antheri- 

 ferous to the top ; styles as numerous 

 as the cells of the ovary ; ripe carpels 

 seceding from the columella. 



Malope, L. 



Althaea, L. 



Malva, L. 



Sida, L. 



Tribe 2. UBBNEJB. Herbs. Sta- 

 minal column destitute of anthers at 

 the top ; styles twice as many as the 

 cells of the ovary ; fruit as in Tribe 1. 



Pavonia, L. 



Urena, L. 



Tribe 3. HIBISCEJE. Herbs or 

 undershrubs. Styles as many as the 

 carpels ; fruit si/ncarpous, capsular. 



Hibiscus, L. 



Gossypium, L. 



B. Andrcecium tubular at the base 

 only, or divided throughout into 

 Jilaments. 



Tribe 4. BOMBACE^E. Large 

 trees or shrubs. Staminal column 

 divided into 5 or more divisions, each 

 with one or more anthers; styles 

 coiiftuent or equal to the carpels; 

 fruit syncarpous, dehiscent or inde- 

 hiscent. 



Adansonia, L. 

 Bombax, L. 

 Durio, L. 



Affinities, &c. The {< compound " stamens of these plants appear first in 

 the form of five little tubercles, the primordial stamens ; from the sides of 

 these are subsequently developed others. The anthers are bilocular in the 

 first instance, but become 1-celied by the obliteration of the partitions. 

 Where the stamens are superposed to the petals it is probable that the 

 latter are not autonomous organs, but outgrowths from the stamens. The 



typical formula may be thus written, S 5 P 5 A 5 G 5, variations being de- 



x 



pendent on cohesion, adhesion, multiplication, &c. Malvaceae are closely 

 allied to Sterculiaceas and Tiliacese (especially to the first, which, in- 

 deed, are only kept separate for convenience' sake) by the general structure 

 and the aestivation of the calyx, but are distinguished by their 1-celled 

 anthers j to the Geraniaceee they are related by the monadelphous 



