HYBRIDS AMONG BRITISH PHANEROGAMS 275 



E. Stuarti Linton was described in Ann. Sc. Nat. Hist. 1902, 177, 

 as being derived from E. Mackaii and E. mediterranea (Journ. Bot. 

 1902, 363). 



Plumb aginace^. — Limonium vulgar e Miller X L. humile Miller 

 (Statice Limonium x rariflora) was reported by me from Bosliam, 

 Sussex (Journ. Bot. 1902, 41), and agreed to by Mr. Marshall, who 

 gathered it with me, and by Mr. 0. E. Salmon. 



Primulace^. — Primula vulgaris Huds., P. elatior Jacq., and 

 P. veris L. form hybrids each with the others. Mr. Marshall 

 quotes Lloyd [Ft. de VOuest, p. 255, ed. 3) as saying of these three 

 species and P. variabilis Goupil: " Ces plantes cultivees ensemble 

 produisent des hybrides k Tinfini"; but he thinks that in a wild 

 state the hybrids are usually sterile, if not invariably. The 

 Polyanthus of the garden is prolifically fertile ; but though I have 

 long grown P. acaulis x veris on light soil and heavy, I do not 

 think seedlings have ever sprung up round these, as they do about 

 Polyanthus and primrose. Mr. Druce, however, tells me that this 

 hybrid is fertile. Anagallis arvensis x car idea has been brought to 

 mind recently by an interesting paper, showing much acumen, by 

 Mr. James Edwards {Journ. Bot. 1906, 368), who referred to Mr. 

 Trimmer's experiment (Fl. Norfolk, p. 117-118), long familiar to 

 me; Mr, Trimmer crossed the two, and "raised a few plants which 

 bore dark purple flowers, but yielded no perfect seed." Gaertner 

 also crossed A. arvensis and earulea several times, and found them 

 absolutely sterile (Darwin, Origin of Species, chap. ix.). This 

 evidence as to sterility will serve, if the hybrid should be observed 

 in Britain. 



GENTiANACEiE. — Gentiana Amarella x germanica (G. Pamplinii 



Druce (B. E. C. Report, p. 379 (1892), and Fl. Berks, p. 345) ), 

 described from Berks specimens, and reported also by Mr. A. B. 

 Jackson from Hants (B. E. C. Report, 1895, 490, and 1897, 557). 



BoRAGiNACEiE. — Ptdmonaria angustifolia L. from the New Forest 

 and P. officinalis L. from West Suffolk produced a hybrid in 

 Mr. Marshall's garden at Milford; but their areas do not over- 

 lap in this country, so the hybrid cannot be expected to occur 

 in Britain. 



Scrophulariace^:. — Verbascum Thapsus L. has been known to 

 cross spontaneously with V. Lychnitis, V. nigrum, and also in my 

 garden (at Bournemouth) with V. pulverulentum Vill. The latter 

 appeared to be perfectly sterile. Darwin credits the hybrids of 

 Verbascum with remarkable sterility. We have two more hybrids 

 occurring in this country, which V. nigrum makes with V. Lychnitis 

 L. and V. pulverulentum Vill. Dr. Focke's testimony is on the side 

 of sterility in this genus, instancing Y. nigrum x Blattaria, V. Lych- 

 nitis x Blattaria, and T\ virgatum x nigrum (artificially produced 



by Gaertner) as all being sterile. He mentions that Darwin found 

 V. Thapsus x Lychnitis which he planted in his garden to be " quite 

 infertile when left alone ; but when fertilized by the pollen of a 

 parent, it produced a few capsules with 2-5 seeds, whereas the 

 capsules of V. Thapsus contained over 700 seeds.' f Similarly he 



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