i8 NATIVE BRITISH ORCHIDACE^ 



In the Malaxideae hiparis and Malaxis may probably be early exponents of waxy 

 pollinia and of pseudo-bulbs, at first intended to bring these humble and inconspicuous 

 plants of boggy habitats through recurrent periods of drought by the storage of 

 water in tracheids (elongated closed cells). Later the evolution of pseudo-bulbs 

 enabled plants to colonise rocks and even trees, and become the ancestors of some of 

 the marvellous epiphytes of to-day. Corallorhi^a belongs to a different line of descent 

 — an ancient type (headquarters in N. America) of low organisation and a saprophyte, 

 whose development seems to have stopped at an early stage. Epipogon is a unique 

 type. In its low vegetative organisation and coralloid rootless rhizome it is allied 

 to Corallorhii^a. The large basal water-storage cavity replaces the numerous tracheids 

 of hiparis. The floral organisation, however, is extremely high, on a par with that 

 of Orchis. It is the apotheosis of the saprophyte. 



In the Ophrydeas Herminium caters for very small insects, and for the first time we 

 come across two separate viscidia (fitting like caps on the joint of the leg) and lateral 

 stigmas. It shows an early stage in the evolution of the Ophrydeas. Caloglossum has 

 distant viscidia but a central stigma, with a supplementary honey-gland beneath each 

 viscidium. It leads us on to Platanthera, the culmination of this line of descent, 

 specialised for Lepidoptera by its long spur with free honey at the apex and lateral 

 viscidia which adhere to the sides of the head. Gymnadeina is from a different line 

 of descent, for the stigmas are lateral, and the viscidia central and linear for attach- 

 ment to the proboscis of Lepidoptera. G. alhida leads on to Neotinea intacta, which 

 resembles it rather closely, but has evolved the viscidia and pouch of Orchis, wliilst 

 retaining the 3-lobed column of Gymnadenia, with its stigmas on the face of the side- 

 lobes, and also its free honey. 



Anacamptis pjramidalis is of special interest as it affords clear evidence of descent 

 through an existing less highly organised genus. Though sometimes regarded as an 

 Orchis on account of the pouch of the rostellum, it has the 3-lobed column with the 

 stigmas on the face of the side-lobes, the flat 3-lobed lip, the small spur-entrance, and 

 the long slender spur of Gjmnadenia compsea. The extraordinary resemblance of the 

 flower to that of the latter is easily understood if we recognise that it is a Gjmnadenia 

 which has evolved the rostellar pouch, the rounded tubers and the dry spur of Orchis 

 with liquid stored between its walls. It is the climax of the Gymnadenia line of descent. 



Gjmnadenia alhida leads us on to Neotinea (obviously a connecting link), which in 

 its turn leads us through Aceras to the Militares sub-section of Orchis (O. simia, 

 militaris, etc.) with which Aceras is closely connected, its leaves smelling of coumarin 

 like those of O. simia, militaris and purpurea. There appears to be no earlier genus 

 from which the descent of the rest of the genus Orchis can be suggested. The pollinia 

 with their packets of pollen were foreshadowed by Goodjera, the dry spur with liquid 

 between the walls by Epipogon, the two separate viscidia and the downward move- 



