273 
THE BRITISH FORMS OF ORCHIS INCARNATA. 
f , 
By tile Bey. T. Stephenson, l).l)., and T. A. Stephenson, 1).Sc. 
(Plate 569). 
Amongst the Marsh Orchids O. incarnata L. should probably 
be given the premier position, and it is untortunate that it should so 
long have been regarded as a mere form of O . latifolia. Lmmeus 
separated (J. sambucina and O. incarnata from ins U . latifolia in 
ed. 2 of Flora ISuecia (1755), distinguishing O. incarnata from 
O. latifolia by the following (amongst other) characters:—Poliis 
pallide viridibus immaculatis; nec saturate viridibus maculatis .... 
Corollis pailide incarnatis; nec rubris. Petalis 2 dorsalibus totaliter 
retlexis ; nec tantum patulis, nec maculatis.” Except that the dorsal 
petals may be spotted, this agrees quite w ell with the Hesli-coloured 
form which is probably commonest in Britain. The specimen in 
Linnaius’s herbarium is a short plant 17 cm. long, wanting the 
lowest leaf ; those remaining are long and very narrow, 1 dm. by 
8 min., the width being the same for lour-fifths of the length. The 
bracts are long and rather narrow, with an elbow-curve below very 
characteristic of the species. The flowers are small, the spur is 
rather long and narrow, the side-lobes, as well as one can see, are 
broadest towards the base. This plant could hardly be mistaken for 
any other species. 
Nevertheless, much confusion abounds both in the text and 
figures of British fioras. Babington ( Manual , ed. 2, 310; 1847) 
first separated it from O. latifolia as a variety ; this he later (ed. 4, 
318 ; 1854) raised to specific rank, with a variety /3 O. anyust folia 
lteich., of which he places (J. r Jraunsteineri lveich. as a synonym. 
It was C. B. Clarke (m Journ. Linn. 8oc. xix. 206, t. 31; 1882) who 
clearly demonstrated which form of our Marsh Orchids really corre¬ 
sponds to Linnams’s description. He described and figured a Hamp¬ 
shire plant with pale green, unspotted leaves and flowers of a pale 
flesh-colour with a yellowish centre and characteristic lip-pattern. 
A similar form appears as O. latifolia in Curtis’s IT. Loud. fasc. v. 
t. 65, as also in E. Bot. t. 2308 (1811), from which latter the figure 
of O. latifolia in Webster’s British Orchids is taken. Webster 
definitely throws over the forms of O. latifolia with spotted leaves, 
regarding them all as hybrids; the plants with unspotted leaves he 
describes in such a way as to suggest that he had O. incarnata 
mainly in view, though his “ deep purple or port-wine ” flowers may 
well have been U . proitermissa. At any rate, he is on the right track 
as regards his grouping, though he takes an unwarrantable liberty 
with the names. 
A further source of difficulty arose in connexion with those very 
numerous Marsh Orchids with unspotted leaves which have now been 
segregated as O. prceterniissa Druce. For instance, Hall and Ullman, 
in the Winchester College reports, reproduced in Bot. Excli. Club 
llep. 1917, refer to O. prceterniissa as O. incarnata , form ii. Now 
that O. prcetermissa has been so well established, all the difficulties 
J ouenal of Botany.—Vol. 61. |_Noyemeee, 1923.] x 
