THE YOUNG NATURALIST. 



221 



(C, arvensis). It occurs anywhere and 

 everywhere, but is most troublesome 

 in cultivated fields. It is perennial 

 and spreads rapidly by its underground 

 rhizomes, which renders it so difficult 

 of eradication, hence it is also generally 

 found growing in patches. It is dio- 

 ecious — that is, although the flowers 

 are apparently perfect, they are func- 

 tionally unisexual, and in one portion 

 the flowers never ripen their seeds. 

 Although the leaves of this species are 

 prickly, the stem is smooth and spine- 

 less, and the flowers are a pale liliac 

 colour. Generally distributed, although 

 rather rare, is the melancholy thistle 

 (C. heterophyttus), one of the most 

 beautiful and distinct of the group. 

 It loves to grow in damp mountain 

 woods , its large, solitary, purple flower 

 heads nod gracefully ; its stem is spine- 

 less ; and the large, lanceolate, serrate 

 leaves are green above, white and 

 cottony underneath. It derives its 

 common name from its ancient medi- 

 cinal use as a cure for melancholy : a 

 decoction of this thistle drunk in wine 

 was believed to expel all melancholic 

 humours from the body and make a 

 man merry; even the root carried 

 about with one was said to do the like, 

 and Culpeper says, "Let them laugh 

 that win : my opinion is that it is the 

 best remedy against melancholic dis- 

 eases that grows." 



In dry pastures, particularly on a 

 limestone soil, or . near the sea, the 



remarkably firm, rigid, erect, carline 

 thistle (Carlina vulgaris) may be met 

 with. Yery often it is under six inches 

 and rarely exceeds a foot in height, 

 bearing several abnormally large flower 

 heads, which are so dry, scaly and 

 prickly, as to rival everlasting flowers 

 in their permanence. The long parch- 

 ment-like inner scales of the involucre 

 are highly hygrometric, expanding and 

 spreading outwards in dry weather, 

 again becoming erect and collapsing 

 inwards during damp. This property 

 they retain for. a long time, and they 

 are often hung up in rustic cottages 

 as natural barometers. Its name is 

 derived from the legend that it was 

 pointed out to Charlemagne by an 

 angel as a specific for the cure of a 

 plague in his army. Our other native 

 species are C. acaulis, remarkable for 

 its apparent absence of stem, the flower 

 heads appearing in the centre of the 

 rosette of radical leaves ; a noisome 

 weed, infesting the dry cultivated fields 

 in the southern counties. The woolly 

 thistle (C. eriophorus) is very local in 

 its distribution ; it is easily recognised 

 from the dense-felted coating of hairs. 

 C. pratensis is found in wet places in 

 various places, and C. tuberosum occurs 

 in two or three localities : these two 

 are so closely allied as scarcely to be 

 held distinct by many botanists. Hy- 

 brids are of very frequent occurrence 

 amongst all the thistles, which adds to 

 the difficulty of their classification. 



