542 



DICOTYLEDONES. 



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

 has twisted cestivation (the upper 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 ring or glands, is 

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

 exceptions, are opposite and without stipules. Endosperm laro-e 

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



The Apocynacese and the Asclepiadacefe, on account of the free ovaries, 

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

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

 Logauiaceaj form a transition to the Rubiaceas. 



The orders are : 



A. STAMENS 5. 1, Geutianaceaa ; 2, Apocynacea?; 3, Asclepiadaceas ; 4, Loga- 

 niaceae. 



B. STAMENS 2. 5, Oleacese ; 6, Jasminaceaj ; 7, Salvadoracese. 



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 A), which finally 

 become transformed into uni pared scorpioid cymes; the parts of 



the flower are 4-5-merous as far as 

 the gynoeceum, which is 2-merous ; 

 the calyx frequently is almost poly- 

 sepalous ; the corolla has distinctly 

 twisted aestivation (the upper edges 

 being free) (Fig. 581 A), except 

 Menyanthece. The carpels are en- 

 tirely united, and most frequently 

 form a \-locular ovary with 2 pa- 

 rietal placentce bearing many ovules 

 (often in several rows, Fig. 581 D, 

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

 cidal dehiscence, the incurved edges 

 bearing the seeds (Fig. 581 D, F). 



I. GENTIAXE.E. 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. 

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



FIG. 580. Erythrcea. Inflorescence. 

 1, 2, 3, etc., the successive shooc- 

 generations. 



