6o6 



ANGIOSPERMAE—DICOTYLEDONES 



' Pyreneenbl.,' p. 363.) — This species is monoecious. Twenty to thirty male disk- 

 florets with a considerably larger number of female ray-florets are aggregated into 

 a head 4 mm. in diameter. Conspicuousness is enhanced by the cauline leaves, 

 which are covered with a thick white hairy coat and surround the corymb of tiny 

 heads to form a whitish star of 20 to 40 or 50 mm. in diameter. 



The ray-florets possess a narrow corolla-tube 2^-3 mm. in length, and 

 secreting no nectar. The style, of which the branches are closely beset with 

 stigmatic papillae internally, projects i mm. from it. The style is covered 

 externally with short sweeping-hairs for some distance below the point where it 

 divides. In male flowers the style does not bifurcate, and therefore possesses 

 no trace of stigmatic papillae. It is in the form of a cylindrical rod covered 

 with papillose sweeping-hairs at its end, and serving to brush out the pollen 

 from the anther -cylinder. These pseudo-hermaphrodite male florets possess a 



Fig. 198. Gnaphaliunt Leontopodium, L. (after Herm. Muller). A. Group of seven heads (nat. 

 size). B. Female ray-floret without the pappus ( x 7). C. Male disk-floret, do. ( x 7). D. End of 



the style of a male floret, which acts as a brush ( X 80). E. Do. of a female floret (x 80). /j sweeping- 

 hairs ; gr^ style ; ffi', ovary ; po^ pollen-grains ; st^ stigmatic papillae. 



corolla-tube about 2 mm. in length, expanding into a bell scarcely i mm. long, 

 from which the anthers and style project. Nectar is secreted at the base of the 

 style. Schroter describes nectar-florets, which resemble the male ones. They 

 possess a vestigial rudimentary style with quite short sweeping-hairs, but no 

 stamens (Ber. Schweiz. Bot. Ges., v, 1895, p. 5). 



Kemer states that the stigmas of the female florets become receptive several 

 days before the pollen of the neighbouring pseudo-hermaphrodite male florets is shed. 



According to MacLeod, the species appears in the Pyrenees in the sub-alpine 

 and lowest mountain region, where it possesses a considerably different habit. It is 

 there more vigorous ; the heads are more numerous, and more loosely aggregated ; 

 and the woolly leaves which surround the entire inflorescence are relatively longer. 



Visitors. — These are very few. MacLeod saw a Muscid : Herm. Muller 

 observed a beetle, a Muscid, and Thrips. 



