440 



DICOTYLEDONES. 



aromatic properties, and differs also in the position of the nectary, in the 

 flowers, which are often irregular with a reduction in the number of stamens, 

 and in the ovule which is usually ascending with micropyle pointing downwards 

 (the Terebinthinfe having the micropyle turned upwards), etc. It is also related 

 to Frangulinae, the Staphyleaceae being the chief connecting link ; but the 

 vEsculinze generally have compound leaves. 



Order 1. Staphyleacese. Leaves opposite, often compound. Flowers 

 regular, , 5-merous in calyx and corolla, 5-stamened. The stamens are placed 

 outside the nectary. Ovary syncarpous or 2-3-partite with free styles. The 

 capsule is thin, bladder-like, 2-3-locular, opening at the apex, and has several 

 very hard seeds with a shining testa without aril. Endosperm. Staphylea 

 pinnata (^.Europe) and trifoliata (N. Am.) are cultivated in gardens; they 

 have white flowers in pendulous, axillary racemes or panicles. 16 species. 

 Staphylea is found in the Tertiary of N. America. 



Order 2. Melianthaceae. Glaucous shrubs with scattered, pinnate leaves, 

 and large stipules. Meliaitfhu*, 8 species ; S. Africa. 



Order 3. Sapindacese. Trees or shrubs, often climbing by 

 tendrils (lianes with anomalous structure of the stem) and with 

 compound leaves. The flowers, in most cases, are small, insigni- 



471. 472. 473. 



FIGS. 471-473. JEsculus hippocastanum. 



FIG. 471. Diagram of the flower and of a scorpioid cyme. FIG. 472. Flower in 

 longitudinal section. BIG. 473. Seed in longitudinal section. 



ficant, and without scent, and in some polygamous and zygo- 

 morphic. S4-5, P4-5, A8 (less frequently 5-10) inside the nectary 

 (disc) ; ovary generally 3-locular, with 1-2 ovules in each loculus 

 (raphe ventral, micropyle turned downwards). Seed without 

 endosperm, often with an aril. The embryo is often thick and 

 curved (Fig. 473). 



jffisculus (Horse-Chestnut). Trees with opposite, digitate, den- 

 tate leaves without stipules ; the inflorescence is composed of 

 unipared scorpioid cymes arranged in a pyramidal panicle (termed 

 a thyrsus). The flowers are irregular, with an oblique plane of 



