96 WAYSIDE AND WOODLAND FERNS. 



spore capsules. Many fronds, however, consist solely of the 

 oval blade, and bear no spike of fructification. The spore 

 capsules open each by a transverse slit, and the spike is then 

 thought to resemble a serpent's tongue. These capsules vary 

 from six to twenty, according to the size of the plant, and the 

 rough spores are ripe in May and June. Whilst it is still 

 summer the frond shrivels and the plant disappears entirely 

 underground ; but if potted and grown in a cold greenhouse it 

 will keep its fronds green and fleshy till winter. (Plates 103, 104.) 



The Adder's-tongue may be looked for throughout Great 

 Britain and Ireland, particularly where the soil is loamy. In 

 the Lake District it ascends to icoo feet. On the Continent of 

 Europe it is widely distributed, as well as over a considerable 

 portion of Asia, and parts of Africa ; the temperate parts of 

 North America and the temperate regions of the Southern 

 Hemisphere. 



There is a variety ambigua, smaller than the type in all its 

 parts, and with a proportionately narrower blade. It has been 

 found in Scilly, North Wales, Shetland, and Orkney. A still 

 smaller form is regarded by some as a sub-species, by others as 

 quite distinct. It is more probably a sub-species connected 

 with the type by the var. ambigua, which is intermediate. 

 This is 



The Small Adder's-tongue (Ophtoglossttm lusitanictim}, which 

 has a more tuberous rootstock, a blade that is oblong or 

 lance-shaped and only an inch long. The spike is not more 

 than half an inch, and the spores contained in the capsules are 

 smooth, whereas those of the type have their surface roughened 

 by little tubercles. An important difference in the two, apart 

 from that of stature, consists in the autumnal, production of 

 fronds in O. lusitanicum, which subsist only till the spring. 

 This indicates that the Small Adder's-tongue must be sought 

 at a different season from that in which the larger species is 

 above ground. The spores will be found in January and 



