KNOWLEDGE OF THE MUTATING OENOTHERAS. 39 



evidence that 0. LamarcMana is in this sense any more " impure " than 0. grandiflora. 

 Eurther, while there is no indnhitahle evidence that 0. LamarcMana was introduced 

 from America previous to 1686 having just the characters it has now, yet I can find no 

 reason for supposing that the large-flowered plants of Ray (1686), Tournefort (1700), and 

 Barrelier (1Y14) helonged any nearer to O. grandiflora than to O. LamarcMana. 



The fact that 0. LamarcMana has not been found wild in North America during the 

 last half-century cannot be used as a valid argument for its origin as a hybrid in 

 European Gardens, for several reasons. (1) Certain races of O. biennis also are now 

 known only in Europe and seem to have disappeared from America. (2) It is evident 

 that, at least in the Eastern States, which have been longest settled, the open-pollinated 

 forms such as O. grandiflora have become practically extinct since the introduction of 

 civilization, while the self-pollinating O. biennis and 0. mtcricata races are still found 

 abundantly in the East as well as the West. This might be anticipated, for in self- 

 pollinated plants, flowering is sure to be followed by seed-production, while in open- 

 pollinated species the flowers are often very imperfectly pollinated. Hence, with the 



enemies resultino; from the advent of civilization, species such as 0. grandi- 



_ v.^^^^* *. j3 



flora and O. LamarcMana, which are open-pollinated, would soon reach a condition in 

 which their seed-production was insufacient to maintain the race, while plants with the 

 close-pollinating habit would not be adversely afi'ected. That the close-pollinated species 

 of Oenothera produce many more seeds than the open -pollinated when left to themselves 

 under the same conditions, is a matter of direct observation in my own cultures, so that 

 it is not surprising that in the Eastern States, which have been longest occupied by 

 civilized man, the open-pollinated species should have become extinct. 



On the other hand (3) many open-pollinated forms still remain in the Western States, 

 which are more recently and less densely populated. As recently as 1867 a specimen 

 was collected in Colorado (see Gates, 1911 d, p. 589) which appears almost identical 

 with 0. rubrinervis, a mutant from 0. Lamarckiana. A new species (0. oruata), 

 evidently closely related to O. grandiflora, was described from Idaho only last year 

 (Nelson, 1911). It is evident, then, that forms at least very closely related to 

 O. LamarcMana are still to be found in the Western States, and there remains at present 

 no sufficient reason for assuming that O. LamarcMana originated only in cultivation. 

 Its mixed ancestry, on the other hand, must be admitted by all who carefully 

 consider the question. But this condition it shares with O. grandiflora, 0. Eookeri, 

 and indeed with all open-pollinated plants in which mongrel races are fertile. 



ards the oridnal distribution of these species in North America, it seems quite 



J_«XV^^ vxxv, v^^x_, 



evident that the large-flowered forms, including both O. grandiflora and 0. LamarcMmia, 

 originally extended from the Eastern Atlantic region of ** Virginia" westward to Texas, 

 and it is certain that 0. grandiflora extended at least from Virginia to Alabama. The 

 physiological behaviour of this species in cultures indicates that the race now surviving 

 in Alabama is adapted to a somewhat more southern climate than O. LamarcMana. 

 It is stated, however (Macoun, 1883, p. I7l), that O. grandiflora is common in 

 Ontario. I have not seen this form to determine its exact cliaracters. From the data 



1)2 



