A SHORT PAPER ON IRIS. 



29 



of Iris," published first, I believe, in the Gardener's Chronicle 

 during 1876, but since revised and enlarged, gives, as a suitable 

 method of distinguishing the various groups into which Iris falls, 

 the varying characters of that very conspicuous raised line running 

 along the middle of the outer or drooping petal-fall of the flower. 

 In the two groups of bullous and 11 beardless " this line is a raised 

 or convex ridge. In two other groups there is a more or less 

 thick line of hair-like bristles, coloured to attract attention, and 

 making believe that it is covered with pollen. In a fifth, the 

 Oncocyclus group, the ridge of hair is spread out as a broad, flat 

 cushion. Joining in with this are one or two which have hairs 

 ridged upon both falls and standards, outer and inner petals re- 

 spectively. A sixth section has the line produced into a crest or 

 comb, cut and frilled very much in the same manner as a 

 cock's. In each and all of these groups there are slight 

 exceptions, as you might expect, which serve, perhaps, to 

 unite the whole. Bulbous Iris, for instance, as Dr. Foster's 

 work* upon this branch of the subject shows us, develops a 

 crest in one or two species in the South Caspian region ; in 

 one species, that of Iris Boisseri in Spain, it develops hair ; 

 and, lastly, in I. nepalensis, its bulb is reduced to a resting bud. 

 This has also a branched inflorescence, which connects it in a 

 manner to the beardless rhizomed species. The beardless again 

 makes a change in I. liexagona, which is furred as though 

 connecting with the true bearded. The bearded Irises again 

 connect with Oncocyclus in lupina, which has the hairs collected 

 to a ridge, but its inner petals have scattered hairs towards the 

 base, as in other members of that section. A tendency to the same 

 is observable in germanica, pallida, and other tall bearded Iris. 



The real use in all these varying developments of this, one 

 might almost say, organ is apparently to make an insect step 

 high upon entering the flower (although I have observed small 

 flies feeding apparently in a persistent manner upon some pos- 

 sible exudation at the base), so that its back shall perforce rub 

 against the just pouted lip of the overhanging stigma, and so 

 deposit any pollen it might have previously collected upon it 

 before entrance into the flower itself. In my own garden, 

 when I first grew Iris, no humble-bee in my locality could 

 understand the flower at all, and after climbing all over the 

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