III4 



THE NATURE BOOK 



^f 



BROOM. 



of the hardened splines, amongst wliich 

 are the rather untidy-looking clusters of 

 pods in their brown calyx-sheaths, darken- 

 ing as they ripen. But in June, and it 

 may be in July, the Petty Whin is in bloom, 

 bridging the space of intervening timj 

 till the Dwarf Gorse is able to take up the 

 tradition. Then the bright gold gleams 

 beside the purple heather bloom, afford- 

 ing one of the most effective of Nature's 

 contrasts, and, incidentally, justifying the 

 faith of lovers in the truth and fitness of 

 their ancient saw. 



The Gorse practically has no leaves ; 

 these, as already mentioned, have been 

 converted to other forms and uses. 

 There is evidence that the ancestral form 

 of leafage was that of the trefoil, a com- 

 pound leaf consisting of three distinct 



leaflets. The early leaves 

 of the seedUng are of this 

 form, though these are im- 

 mediately succeeded by 

 simple ones, narrow, 

 gradually stiffening into 

 spines. On the mature 

 plant, apart from these 

 spines, no vestige of a 

 leaf remains larger than a 

 minute scale. 



In the course of its 

 evolution the Gorse has 

 adapted itself to the en- 

 durance of excess of heat 

 and drought. Its com- 

 pound leaves have been 

 changed to simple ones ; 

 these have narrowed to 

 the spinous form, reducing 

 evaporation to a minimum. 

 So the Gorse is able to 

 grow and flourish on the 

 dry heath, exposed to the 

 full glare of the sun. Here 

 another necessity has 

 arisen, that of ])rotection 

 against browsing animals. 

 So these narrow leaves 

 have hardened into spines, 

 stiff and sharply pointed 

 as a shoemaker's awl. 

 Every projecting twig 

 also has become pointed, 

 itself a true thorn, ringed 

 round with outstanding 

 spines, sharp and strong. 

 So the Gorse is armed cap-a-pie, leaving 

 no part defenceless. Yet these hardened 

 spines and thorns are directly due to the 

 condition of dryness wherein the Gorse 

 now flourishes. If seedlings be grown in 

 a continuous moist air, as under a hand- 

 glass, it will be found that, though in the 

 first year, through sheer force of habit, 

 a few shortened spines will appear, yet in 

 succeeding years, so long as the state of 

 moisture is maintained, there will be 

 none — only soft, fleshy leaves. As is 

 often the case with plants adapted to 

 withstand drought, every ])art of the 

 Gorse is densely coated with minute hairs 

 forming a velvety pile. Twigs and 

 branches are furrowed, and, like the 

 spines, are green in colour. 



The fl(jwers grow singly or in pairs at 



