542 DICOTYLEDONES. 



2 (nearly always median) carpels. The corolla very frequently 

 has twisted cestivation (the tipper edges of the petals being free 

 Fig. 581 A), and hence the individual lobes of the corolla are 

 oblique, but the flower as a whole is regularly actinomorphic. 

 A nectary, in the form of a honey- secreting ri^g or glands, is 

 often found round the base of the ovary. The leaves, with a few 

 exceptions, are opposite and without stipules. Endosperm large 

 (Fig. 581 (7), except in Jasminacece and Asclepiadacece. 



The ApocynaceaB and the Asclepiadaceae, on account of the free ovaries, 

 without doubt represent a more primitive form, but the Asclepiadaceas on the 

 other hand form an offshoot on account of their peculiar pollen-masses. The 

 Loganiacese form a transition to the Rubiaceae. 



The orders are : 



A. STAMENS 5. 1, Gentianacese ; 2, Apocynacese ; 3, Asclepiadace ; 4, Loga- 

 niacese. 



B. STAMENS 2. 5, Oleaceae ; 6, Jasminaceee ; 7, Salvadoraceae. 



Order 1. Gentianaceae (Gentians). Glabrous herbs, with- 

 out latex ; the opposite, undivided and entire leaves are often 

 slightly united at the base ; many have rosette-like radical leaves, 

 Stipules absent. The flowers are generally borne in regular, 

 dichotomously-branched dichasia (Figs. 580, 581^1), which finally 

 become transformed into uni pared scorpioid cymes ; the parts of 



the flower are 4-5-merous as far as 

 the gynoeeeum, which is 2-merous ; 

 the calyx frequently is almost poly- 

 sepalous ; the corolla has distinctly 

 twisted aestivation (the upper edges 

 being free) (Fig. 581 ^4), except 

 Menyanthece. The carpels are en- 

 tirely united, and most frequently 

 form a I-locular ovary with 2 pa- 

 rietal placentae bearing many ovules 

 (often in several rows, Fig. 581 I), 

 F). Capsule, 2-valved, with septi- 

 FIG. 580,-BrytJirao. inflorescence, cidal dehiscence, the incurved edges 

 i, 2, 3, etc., the successive shoot- bearing the seeds (Fig. 581 D, F). 



I. GENTIANEJ:. Gentiana (Gen- 

 tian) has most frequently a tubular, campanulate or funnel-shaped 

 corolla, sometimes with teeth between the corolla-lobes and fringed 

 in the throat of the corolla; G. lutea has a rotate, yellow corolla. 

 Swertia : rotate corolla ; each lobe has at its base 1-2 nectaries, with fringed edges. 



