THALAMIFLOR^E. 



223 



or irregular, frequently unisexual by abortion ; calyx and corolla resem- 

 bling those of Malvaceae or petals absent; androecium columnar or tubu- 

 lar, or rarely stamens few, free ; anthers 2-celled and extrorse, in heads 

 or rings or dispersed, with or without intervening staminodes ; carpels o, 

 rarely 3 or solitary, distinct or coherent, often pedicellate ; fruit and seeds 

 very variable. 



ILLUSTRATIVE GENERA. 



Tribe 1. STERCULIE^. Floivers 

 apetalous and unisexual by abortion; 

 anthers clustered or annular. 



Heritiera, Ait. 



Sterculia, L. 



Cola, Schott. 



Tribe 2. HELICTEREJE. Flowers 

 perfect; petals deciduous. Andrcecium 

 columnar below, cup -shaped above; 

 staminodes on the margins of the cup, 

 alternating with the anthers. 

 Helicteres, L. 



Tribe 3. ERIOLVENIE^. Flowers 

 hermaphrodite; petals deciduous. An- 

 droecium tubular, conical, antherife- 

 r ous for nearly its whole length. 

 Eriolaana, DC. 



Tribe 4. FREMONTIE^. Flowers 

 hermaphrodite ; stamens conjoined ; 

 anthers 5 ; staminodes ivanting. 



Fremontia, Hook. 



Cheirostemon, L. 



Tribe 5. DOMBEYEJE. Flowers 

 hermaph rodite ; petals fat, persistent. 

 AndrcBcium tubular, antheriferous at 



the marc/in; anthers solitary or in 

 groups, alternating with staminodes. 



JJombeya, Cav. 



Melhania, Forsk. 



Tribe 6. HERMANNIE^J. Floioers 

 hermaphrodite ; petals persistent, 

 twisted in (estivation. Androecium 

 tubular at the base only ; staminodes 

 wanting. 



Hermannia, L. 



Waltheria, L. 



Tribe 7. BUETTNERIE^E. Petals 

 concave at the base ; androecium 

 tubular ; anthers marginal, solitary, 

 or in groups between the staminodes. 



Buettneria, L. 



Abroma, Jacq. 



Leptonychia, Turez. 



Tribe 8. LASIOPETAL^E. Flowers 

 hermaphrodite ; petals or scale-like 

 or lanceolate. Androecium tubular 

 below, bearing above five anthers and 

 as many staminodes, the latter oppo- 

 site the sepals or ivanting. 

 Thorn asia, Gay. 

 Lasiopetalum, Smith. 



Affinities, &c. The usually 2-celled anthers separate the plants of this 

 Order from the Malvaceae, the monadelplious condition from the Tiliaceae. 

 Nevertheless the distinction between this Order and Malvaceae is purely 

 artificial, and is here retained for convenience' sake only. 



Many plants of this Order are interesting in structural respects. Dela- 

 bechea (Australia), Brachychiton, and others have a trunk swollen midway 

 between the ground and the crown of the tree, giving the appearance of 

 a huge flask or bottle. Helicteres is so called from its twisted follicles ; 

 the pods of some Sterculiece open out like leathery leaves with the ripe 

 seeds on their margins. The species of Sterculia and Cola are remarkable 

 for the variable condition of their seed, some having perisperm, others not ; 

 the direction of the radicle with reference to the hilum is also different in 

 different species. Cola has often three or four cotyledons, or perhaps 

 two, deeply divided. The pollen is ovoid with three plaits, or globose or 

 polygonal, not muricate except in Dombeyece. 



