230 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



as /. laevigata syn. 7. Kaempferi. These two names have long been in 

 horticultural use, but their association only serves to perpetuate an 

 obvious confusion. One would have thought that even the most 

 rapid consideration of the common Japanese Irises would have driven 

 us to question the suitability of the name laevigata, which means 

 " smoothed." Their leaves are rough, with a prominent central rib ; 

 the seeds are wrinkled, the petals crimped, and indeed it is hard to see 

 what feature could possibly have suggested the name. 



Like several other plants which we associate with Japan, such 

 as /. japonica, which comes from the hills near Ichang in Central 

 China, /. Kaempferi is a native of China and grows wild in the marshes 

 along the Amur. In its natural state it appears to be always single, 

 and there is no accepted explanation of the means by which the 

 Japanese have evolved from it the long series of double, distorted 

 and even bloated hybrids with which the student of Japanese art 

 has long been familiar. In the natural state the colour is a deep 

 red-purple, though albino forms most undoubtedly occur. In the 

 famous ditch which runs through the lower corner of the Wisley 

 garden, /. Kaempferi has now been growing for many years since 

 Wilson first planted there importations from Japan. Innumerable 

 seedlings must have grown up there in the course of time, and it is 

 interesting to notice that the self-sown reversions to the single wild 

 form of a uniform red-purple or white now far outnumber all the 

 other forms to be found scattered among them. 



I. laevigata is also a native of the Amur marshes and may be 

 easily distinguished by its foHage, which is smooth and has no prominent 

 central rib, and by its large smooth polished seeds, which closely 

 resemble those of our native yellow water Iris, /. Pseudacorus. The 

 colour is purple, usually of a blue, but sometimes of a red, shade, 

 with a narrow central streak of yellowish white. Good forms of 

 this species are, I think, undoubtedly among the finest blue Irises 

 that we possess. 



Curiously enough, this Iris also first reached us from Japan in 

 the form of a quasi-albino variety, which came to Kew mixed with 

 I. Kaempferi, and which was separated by Mr. Baker and described as 

 /. alhopurpurea. We must accordingly reduce this name to /. laevigata 

 var. alhopurpurea and try to realize that the two names laevigata and 

 Kaempferi represent two totally different species. Among collected 

 material now preserved in herbaria I have found no evidence that 

 natural hybrids of these two species occur, and efforts to cross them 

 in the garden have so far proved futile, though I should be the last 

 to attach any great value to such purely negative evidence. Of the 

 conditions that determine the fertility of an Iris little is yet known, 

 and, after succeeding quite unexpectedly in crossing a bearded Pogon- 

 iris with a crested Evansia, although many previous efforts had 

 always resulted in failure, I am incHned to think that it may not be 

 impossible to cross any two members of the genus. 



In this connexion, may I suggest to the hybridizer the interest 



