512 



DICOTYLEDONES. 



A 



FIG. 518. Primula.- <limorphic flowers. 

 A short-styled ; B long-styled. 



Order 1. Primulaceae (Primroses). This order has many 

 ovules attached to a thick, free, central placenta (Fig. 547) ; style 



undivided with a capitate stig- 

 ma ; ovules semi-anatropous ; 

 fruit a capsule with many seeds. 

 All the plants belonging to 

 this order are herbs ; stipules 

 wanting ; the flower is most 

 frequently 5-merous (S5, P5, 

 AO + 5, G5 ; except Centunculus 

 and Trientalis). The corolla 

 and capsule have various forms, 

 but the capsule generally opens 

 by teeth at the apex. The 

 ovules are semi-anatropous (in 

 Hottonia they are anatropous), 

 and the seeds are therefore 

 peltate, with the hilum situated in the centre of one side. The 

 endosperm is fleshy or horny. The flowers are borne either in 

 racemes or in umbels; as bracteoles are typically absent (Fig. 547), 

 cymose branching does not occur. 



Primula (Primrose) has most frequently a vertical rhizome, 

 bearing a rosette of leaves at its summit, and long-stalked umbels; 

 corolla rotate or slightly f utmel-shaped ; the capsule opens at 



the apex by 5 teeth. 

 The flowers in some 

 species are hetero- 

 styled (long- styled 

 or short-styled ; Fig. 

 548). Closely allied 

 are Androsace (with 

 ovate, cup-shaped 

 corolla-tube and 

 ligular scales, alter- 

 nating with the 

 corolla -lobes) and 

 Soldanella (funnel- 

 shaped corolla with 

 laciuiate lobes and 



FIG. 510. Cyclamen pens. 'cum. 



most frequently ligular scales). Hottonia (Water- Violet) is an 

 aquatic plant with pectinate leaves and heterostyled flowers. 



