DIPSACALES. 



559 



(Figs. 597, 599, 600), which envelopes the inferior ovary. The 

 flowers (Figs. 599, 600) are $ , 5-merous (S5, P5, stamens typi- 

 cally 5, Gr2), but the calyx often expands at the edge into 

 a membrane with 5, or an indefinite number of bristles or teeth 

 (pappus, Figs. 597, 600), and the zygomorphic, funnel-shaped corolla 

 is sometimes 5-lobed and bilabiate (f), but most frequently 4- 

 partite (Fig. 599), the two lobes of the upper lip coalescing into 

 one lobe, as in certain Labiatse, Veronica and Plantago; the 

 aestivation is imbricate. 



GOO. 



598. 509. 



FIG. 598-600. Dipsacus fullonum. 



FIG. 598. Inflorescence (the flowers in a zone below the apex commence to flower first). 

 FIG. 599. Flower (j). FIG. 600. The same in longitudinal section. 



The stamens are never more than 4, the posterior one remaining 

 undeveloped; they usually have free anthers which generally project 

 considerably (Fig. 599). The ovary is unilocular with 1 pen- 

 dulous ovule and bears 1 undivided style ; fruit a nut with 1 seed, 

 containing endosperm and with the radicle turned upwards (Fig. 597). 



The flowers do not always open in centripetal order, a fact which may be 

 observed especially in the Dipsacacess, in which a zone of flowers round the 

 centre of the capitulum opens first, and the flosveriug then proceeds both up- 

 wards and downwards (Fig. 598). This has probably some connection with the 

 fact that the capituluin has arisen from the coilescence of several dichasial 

 inflorescences. In species of Scabiosa the flowers open simultaneously at the cir- 

 cumference, or in a zone at the centre. The morphological explanation of the 



