544 



PART IV. CLASSIFICATION. 



derived from their walls ; the various parts of the flower and the fruit 

 (p. 97) contain much ethereal oil : the leaf, which is typically pinnate, is 

 reduced to its terminal leaflet which is articulated to the winged petiole 

 (Fig. 23 (?); the leaf is sometimes spinous. 



Fio. 355. Flower and aoral diagram of Citrus. A Open flower ; c corolla; s the partially 

 connate stamens ; n the stigma. B Bud ; fc calyx; c corolla; d oil-glands. 



Citrus medico is the Citron; C. medica var. Limonum, is the Lemon; C. 

 medico var. Limetta, is the Lime; Citrus Aura nti um var. Bigaradia (or C. 

 vulyaris) is the Bitter or Seville Orange, and C. Aurantium sinense is the 

 Sweet Orange; Citrus nobilisis the Mandarin Orange ; and Citrus decumaua 

 is the Shaddock: all originally derived from tropical Asia- 

 Cohort II. Sapindales. Flowers typically pentamerous and 

 obdiplostemonous but with reduction in the andrcecium, actino- 

 morphic or zygomorphic, sometimes unisexual : gynseoeuin 

 oligomerous, usually syncarpous. Mostly trees. 



Order 1. SAPIXDACE.E. Flowers usually irregular, obliquel}* 

 zygomorphic or asymmetric, in that the two petals of one side are 

 larger and of somewhat different form to the three others ; of these, 

 one, which lies in the plane of symmetry, is sometimes wanting 



FIG. 350. Floral dia- 

 gram of JEsculus': but 

 the missing stamens 

 should be represented 

 us antisepalous. 



FIG. 357. Fruit of A. platanoides, dividing into tv 

 mericarps in ; s pedicel ; ;! wings (nat. size). 



