HYBRIDISM 33 



if nothing else could.. . .Perhaps my intermediates between Habenaria (Platanthera) 

 chlorantha and hifolia (of wlaich I retain a lively recollection) were of this hybrid 

 nature". Hybrids between genera were still more unthinkable. Wettstein urged the 

 inclusion of Cephaknthera in the genus Epipactis on the strength of a single specimen 

 of the cross C.grandiflora {^aliens) x E. nibiginosa, maintaining that the very existence 

 of this hybrid pleaded for the union of these two genera.^ 



One of the first natural hybrids recognised was Gjmnadenia conopsea by Nigriteila 

 nigra, found near Grenoble in 1787, and named Orchis smveolens by Villars.^ Neither 

 of the parents is now regarded as belonging to the genus Orchis. This was followed 

 by Orchis hybrida Bonningh. in 1830, found growing amongst the parents, 0. militaris 

 and O. purpurea, and regarded by Lindley as a mere variety.3 In 1852 a consignment 

 o£ Phalampsis aphrodite {amabilis) contained a plant which Lindley regarded as P. ama~ 

 bilis X P. rosea (xP. intermedia). Later Seden fertilised P. amabilis with pollen from 

 P. rosea. Only one seedling was successfully raised, which flowered in 1 8 86, and turned 

 out to be identical with the wild plant, confirming Lindley's determination. This 

 appears to have been the first actual proof by experiment of the hybrid parentage of 

 a wild orchid. 



Some species cross much more readily than others. Orchis morio crosses fairly 

 frequently with 0. laxiflora, forming x 0. alata Fleury (PI. 42), but very rarely with 

 O. mascuia (PI. 40), though they often grow together. Of the British marsh orchids 

 Orchis incarnata, latijolia, pratermissa and purpurella hybridise not infrequently with 

 0. maculata, and to a less extent among themselves. They are similar enough in 

 appearance to attract, at any rate sometimes, the same insects. Wherever they grow 

 together in any quantity there is a good chance of finding a hybrid, perhaps several. 

 In some localities the intermediate hybrid forms vary "so much as to give some 

 plausibility to the theory that they aU belong to one polymorphic species, but the 

 various species are stable enough over very wide areas of distribution. The great 

 variety in our marshes is probably due, not only to primary hybrids being sometimes 

 nearer one parent, sometimes the other, but to back-crossing of these with one or 

 other parent. A chain of intermediates between two forms does not necessarily prove 

 that they belong to the same species. It is much more likely to be due to hybridism. 

 When a first generation hybrid is crossed with a third species, great variation results, 

 even seedlings from the same capsule showing wide divergence. If the hybrid Ay.B 

 be crossed with C, some of the offspring resemble the hybrid AxC, and some 5 x C, 

 while the rest will form various combinations of the three species concerned, as in 

 the well-known case of Cypripedium aureum (C. insigne x villosum crossed with C. spice- 

 rianum). Artificial hybrids involving no less than six different species have been 



• (Bster. Bof. Zeitung, pp. 395-9 (1889). . p/. Dauphin, u, 38, t. i. 



3 Gen. et Spec. Orch. p. 271. r > > ? > 



