30 NATIVE BRITISH ORCHIDACE^ 



only slightly invaded, the others with undigested coils in the cortex-cells.^ Adventive 

 buds have been found on roots still in living connection with the plant.* 



Penetration of the roots and often of the rldzome is usual in the Neottieas. In 

 Epipactis ruhiginosa the roots are very numerous and long, deeply penetrating the 

 creviced limestone, with flat spear-shaped tips adhering to the rock. Swellings occur, 

 giving rise to new roots and a new shoot (PL ii, F), showing how a rhizome can 

 be formed deep in the rock. PL ii, figs. D and E, show that a shoot can even be 

 formed at the tip of a root. In Listera, mycorrhiza form coils in the cells of the cortex, 

 and are present in the root-hairs, but in L. cordata, according to Chodat and Lendner,3 

 they do not extend outside the hairs. In Neottia (Text-fig. 5), symbiosis is continuous, 

 the fimgus infecting rhizome, roots, and sometimes the base of the stem. Increase 

 may occur through buds at the tips of the roots.3 W. H. Herbert found that some of 

 the fleshy roots, though dead at the base, were alive and beginning to protrude young 

 fibres at the tip,'* the extreme point becoming the eye or shoot. There is no chlorophyll, 

 the leaves being reduced to brown sheathing scales, probably due to the very extensive 

 invasion by endophytes, wliich convey so much nutriment from decaying organic 

 matter that leaves have become superfluous. Bognisia crocea (Burmanniace^) has a 

 similar root-system, which is a sign of saprophytism, found also in our Epipactis 

 violacea (PL 8) and the continental orchid Limodorum ahortivtmi. 



Goodjera repens inhabits the layer of needles and moss in pine-woods, and has a long 

 creeping rhizome, in which the endophyte Rhi^octonia Goodjera repentis is abundant. 

 The specimen figured (PL 13) is the only one we ever found or heard of with a bulb- 

 Hke tuber, and shows the possibility of a slender rliizome giving rise to such. In 

 Spiranthes the roots are long and cylindrical in species growing in wet ground, e.g. 

 S. cestivalis, but thicker in those inhabiting drier places,5 e.g. S. autumnalis, in which 

 they resemble the tubers of Vktanthera hijolia in shape. They are not true tubers, 

 however, being monostelic and infected by fungi, but indicate a passage from the 

 roots of the Neottie^ (to which the above belong) to the tubers of the Ophrydeae. 



Malaxidea. In Malaxis and Liparis the roots are slender. There is a bulb-hke 

 swelling at the base of the stem above the leaves surrounded by several thick tunics, 

 with many tracheids (elongated closed cells) for storage of water. They are slender 

 frail plants, and this provision is necessary to bring them tlirough dry periods wlien 

 the sphagnum or boggy ground in which they grow dries up. Coraliorhi^a has no 

 roots, but a whitish coral-like rhizome with short lobe-like branches largely infected 

 by endophytes. That curious plant Geomitra episcopalis (Burmanniaceas) has a similar 



' Camus, op. cit. pp. 32, 3 5, 47. '^ Irmisch, op. cit. 



3 R. Chodat et A. Lendner, B«//. Uerh. Boisskr, iv, 265 (1896). 



4 Leighton, F/. Shropshire, p. 434 (1841)- r n ■ , t, ^ u 



5 Mr Mousley found that near Hatley, Quebec, the roots of Spiranthes Komanioffiam were much 

 thicker in dry ground than in wetter places. 



