492 



HUTCHINSON'S POPULAR BOTANY 



FIG. 615. WHEAT 



(Triticum). 



A section through the grain 

 or caryopsis. 



interwoven,' somewhat after the fashion of the spider's 

 web. This comparatively intricate structure is given 

 as a countervail to the great size and weight of the 

 seed. The down of Dandelion is supported on a long 

 and slender pedicel, and is an object of vulgar ad- 

 miration ; but it scarcely equals in beauty the simi- 

 larly patterned fruit of the Helmintkia. The Thistle's 

 down is, on the contrary, sessile the threads being 

 sometimes only spinous, at other times plumed like a 

 feather and the down of the latter is peculiarly light. 

 The coronet of the Carline-thistle (Garlina) is remark- 

 able for its elegance and circular spread and plumage, 

 and buoys easily its silky coated seed [i.e., fruit]. In 

 the Sow-thistles (Sonchus) what we most admire is 

 the ribbed and striated seeds 

 [fruits], but the down that diffuses 

 them is abundant and of pure 

 whiteness. The seeds [fruits] of 

 the Coltsfoot (Tussilago) afford an 

 example of a structure, common 



in the order, where the seed [fruit] is surmounted by 



a tuft of silken hairs, armed at regular intervals with 



a series of denticles or spines, only visible with a good 



magnifier. We have a contrast to this in the curious 



fruit of the Blue-bottle (Centaurea cyanus^) : which has a 

 small tuft of asbestine spines at 

 the base, and a large but short tuft 

 of rigid stout lanceolate spines 

 on the top, the edges of each of 

 them indented with close and 



sharp serratures like a saw. This tuft cannot float 

 the seed in the air, but it will obviously direct and 

 hasten its descent into the soil, and it will be re- 

 marked that the forward direction of the spines must 

 be opposed to every influence to cast them up again, 

 after having been buried under the surface." 



We have now dealt with two of the three great 

 classes into which all true Phanerogamic fruits may 

 be divided ; it remains only to speak of the third 

 class viz., the splitting fruits, or schizocarps. 



Schizocarps are multiple, usually indehiscent, 

 fruits, which split into one-seeded portions called 

 mericarps, resembling nuts or achenes. Each of 

 these portions is itself a true fruit. The splitting 



FIG. 616. DANDELION 

 (Taraxacum). 



A eypseJa with stipitate 

 pappus. 



FIG. 617. JOB'S TEARS 



(Coix lachryma). 



A caryopsis. 



