Miller Christy 
238 
points on the rootstock (i.e. the short compact stem from which 
leaves and flowers arise), at or slightly below the level of the ground 1 . 
Often as many as eight or ten pedicels spring from one of these 
points, each having at its base a long narrow lanceolate bract, 
10-12 mm. long and about 1 mm. broad at the base. It is, therefore, 
correct to say that the flowers of the primrose are borne normally 
in umbels—that is, in sessile umbels, the scape or peduncle having 
been suppressed. The umbel is complete, even to the bract which, 
in the other umbellate species of the genus, appears at the top of the 
peduncle, on the outer side of the base of each pedicel. 
The caulescent or umbellate variety of the primrose is, therefore, 
merely a variety in which the plant has developed the peduncle, 
usually suppressed, thereby reverting to an earlier form of inflores¬ 
cence. But why a tendency to this reversion should be more pro¬ 
nounced in one district than in another (as seems to be the case) is 
by no means easy to explain. 
P.S.—Since the foregoing was written. Prof. J. W. Heslop 
Harrison has informed me that, in the north of England, he has 
sometimes met with a plant which, though distinct in origin from 
the caulescent variety of the primrose, resembles that plant so 
closely that it could probably not be distinguished from it by even 
the most careful external examination—and this is a back-cross 
between the hybrid oxlip and the piimrose (namely (P. veris x vul¬ 
garis) x P. vulgaris). 
I have never seen (or, at all events, have never recognised) this 
hybrid in the south of England, where, indeed, I doubt its occurrence; 
but Prof. Heslop Harrison has proved its existence in his district 
by means of cytological tests 2 . He has also produced it by artificial 
1 Curtis’ denial {FI. Londin. 6, p. 16, ? 1790) that this is the case must have 
been due to an error of observation. 
2 In the south, the ordinary hybrid oxlip (P. veris x vulgaris), though it 
occurs wherever its two parent species grow in proximity, is always scarce 
and sporadic (see ante, 21, p. 299); but, in the north, it occurs in places quite 
abundantly. Thus, the late J. G. Baker writes of its two parents (see Journ. 
Roy. Hort. Soc. 7 , p. 212) that “you cannot go into any field in the north of 
England without seeing that they do hybridise most fully [? freely].” In 
Northumberland and Durham, Prof. Heslop Harrison informs me that the 
hybrid oxlip is, in places, extremely abundant, especially on the Magnesian 
Limestone on the coast, whence “countless” plants may be obtained. The 
reason for the exceptional local abundance of this hybrid is, he says, the 
prevalence in early spring of cold north-east winds, which greatly retard the 
flowering of the primrose, especially on the coast, causing the flowering-times 
of it and the cowslip to synchronise much more nearly than elsewhere: hence 
more frequent hybridisation between them. 
