HYBRIDS AMONG BRITISH PHANEROGAMS 297 



gathered at Witley in company with Mr. Marshall. — R. pulcher x 

 rupestris (B. E. C. Rpt 1876, p. 31). — R. obturifolim x pulcher, West 

 Head, E. Cornwall {B.EM. Hpt. 1877-78, 18.).— ^. crispusx domes- 

 ticu*. — jR. crispus x pulcher. — R. crispus x sanguineus I have not 

 seen, but I have sheets of R. crispus x viridis from Malvern, Wor- 

 cestershire, and Radnor. R. crispus x obtusifolius [R. acutus L. 

 R. jnatensis M. & K.) is the most widely spread of our Dock hybrids, 

 and is said by Mr. J. W. White, in the Flora of Somerset, to fruit 

 freely in that county; the Rev. R. P. Murray, however, thinks it 

 fruits only sparingly, and Dr. Focke says, " fruits mostly im- 

 perfect." R. domesticus x obtusifolius (R. conspersus Hartm.) is 

 also said to be fertile like R. pratensis in the B. E. C. Rpt. 1872-74, 

 p. 36, where some good notes on Rumex by J. Boswell Syme 



occur. 



Thymel;eace#;. — Daphne Laureola X Mezereum was recorded by 

 Mr. Marshall from Sussex in 1903 {Joum. Rot. 1903, 230), and he 

 has happily been able to confirm the record of the hybrid by dis- 

 covering a better intermediate, near Somerton, in which the leaves 

 are more or less evergreen, though like P. Mezereum in shape and 



veimng. 



Amentace^:. — Betula pubescens x verrucosa [B. odorata Bechst. ?). 

 To this hybrid Mr. Marshall refers specimens of his own gathering 

 from Lawers, Mid-Perth, and Blair Athol, Perthshire, and of my 

 gathering from Breamore, S. Hants. He also informs me that we 

 have three hybrids of B. nana x pubescens : — 1. B. intermedia 

 Thomas {nana, male x pubeacens, female) ; 2. B. alpestris Fries 

 (nana, female x pubescens^ male) ; and 3, a dwarf plant which ap- 

 pears to him a new form. Mr. Marshall tells me that the late Prof. 

 Babiugton wrote to him about 1889 that B. intermedia formed quite 

 woods in Iceland ; so he infers it is probably fertile [see p. 294] . 



Salix. In Jonrn. But. 1902, p. 330, the following sentence 

 occurs : " Now; according to Wichura, the hybrids of Salix repro- 

 duce themselves like pure species"; and the inference is drawn 

 that Hieracium species have become multiplied and established in 

 the same way. I have already shown how unsafe it is to apply the 

 rule of one genus to another in respect to the characters of hybrids. 

 But the above dictum, attributed to Wichura, is far too general a 

 statement, and can easily be rebutted. Not to rely too much on 

 the well-known variability of some willow hybrids, such as 

 S. viridis Fr. or S. lutescens Kerner, I have myself crossed the two 

 sexes of 8. aurita x Lapponum, and reared the offspring, only to 

 find the greatest variability in the results of one sowing. The 

 hybrids which occur spontaneously in Britain may be shown most 

 clearly by enumerating the unions which each species has been 

 known to make : 



r> 



th / 



fi 



f 



S. purpurea with viminalis, aurita, cinerea, phylicifolia and 



repens 



