414 BRITISH FLOWERING PLANTS 



Crocus 



Protandrous butterfly flowers. We have two 

 species — one C. vernus, flowers in spring ; the other, C. 

 nudijlorus, in autumn. 



0. vernus. — The flowers are white or purple, with stig- 

 mas of a rich orange. Nectar is secreted by the ovary, 

 and is protected by hairs. The tube is much too long for 

 the proboscis of any insects except Lepidoptera, but the 

 nectar sometimes reaches so far up as to be accessible 

 to some of the humble bees. There are two forms of 

 the flower. A small flowered one, with stigmas as long 

 as, or shorter than, the stamens ; and a large flowered 

 one with longer stigmas. The leaves in Crocus are 

 arranged round the stem, not in two rows as usual in 

 the order, and also, unlike those which characterise most 

 of the genera, have a distinct upper and lower face, 

 and the tissues of the leaf are markedly difi'erentiated 

 into palisade cells above, and spongy parenchyma below. 

 When the leaves are young and tender they are rolled 

 up, and do not flatten themselves till they are stronger, 

 and in less danger from frost. 



0. nudiflorus. — Areschoug and Massart have pub- 

 lished^ interesting memoirs on the means by which 

 plants keep to a convenient depth. Plants of Crocus 

 placed on the surface develop fleshy roots, which eventu- 

 ally contract and draw the corm down to a suitable 

 level. On the other hand, if the light is excluded no 

 such contraction takes place. As Eaunkler says, "la 

 plante est completement desorientee dans I'obscurit^." ^ 



Iris 



The flowers are large and showy — the 3 outer 

 perianth -segments large, spreading, and reflexed; the 

 3 inner ones much smaller and erect. The style bears 

 3 large flattened branches, each with an appendage 



^ Aresclioxig, " Beitr. z. Biol, der geophileu Pflanzen," Act. Beg. Soc. Phtjs. 

 Lund. 1896. Massart, "Comment les plantes vivaces maintiennent leur 

 niveau souterrain," Bull. Jard. Bot. Bruxelles, 1903. 



^ Overs, det IC Danske Fid. Selsk. Fork. 1904. 



