110 ON SEEDLINGS 



The ultimate ones are lyrate-pinnatifid. The cotyledons of 

 Gaillardia pinnatifida (fig. 468) are oblong- spathulate and very 

 variable in size according to vigour. The first three leaves are 

 similar but larger and petiolate, while the ultimate ones are 

 entire or sublyrate-pinnatifid. 



The cotyledons of Carduus giganteus are obovate-oblong 

 or spathulate, petiolate, connate at the base, slightly penni- 

 nerved, and shallowly emarginate. The first two leaves are 

 lanceolate-elliptic, spiny, hairy and rather smaller than the 

 cotyledons. Silybum Marianum (fig. 481) has very similar 

 cotyledons. The leaves are variously blotched and reticulated 

 with silvery white. The two first ones are oval succeeded by 

 two or three oblong, and all are doubly spiny-toothed at the 

 margin. Cnicus syriacus has leaves somewhat similarly 

 blotched to those of the last named, and the first six are 

 elliptic or oblong-elliptic and spiny -toothed. The cotyledons 

 are broad and slightly emarginate. Cnicus diacanthus (fig. 

 480) has also broadly spathulate cotyledons, and the first three 

 leaves are oblanceolate and slightly spiny-toothed. The ulti- 

 mate ones are strongly spiny, and all have the midribs and 

 principal nerves of a silvery white. The cotyledons of Tyrim- 

 nus leucographus are oblong and subfleshy. The leaves are 

 irregularly blotched with silvery white as in the case of 

 Silybum Marianum ; the first two are oval and minutely 

 spiny-toothed, succeeded by three others which are oblong or 

 oblong-obovate, lobed and spiny. The cotyledons of Zolliko- 

 feria are spathulate-obovate, trinerved and slightly emar- 

 ginate, and the first two leaves are oval and finely repand- 

 dentate. 



There is no exact line of demarcation between broadly 

 spathulate cotyledons and those which may more rightly 

 be termed obovate, as the one type gradually merges into 

 the other. The obovate type is represented by Venidium 

 calendulaceum. The cotyledons have also a well-marked 

 emargination and the first two leaves are lanceolate, trinerved, 

 hairy and entire. Gitndelia Tournefortii may also be placed 

 here. Its cotyledons have a curious longitudinal furrow, which 

 may or may not be median, and appears to be due to folding 

 while yet in the seed. The seedling of Berkheya purpurea 



