184 On the Species of the Genus Primula in Essex.
the limit of stalk-development does not end here, as I
have on several occasions picked fasciated stalks of much
greater width. For instance, on April 29th, 1882, I obtained
two in Pounce Wood, each of which was over 1 inch broad,
not thicker than usual, about 6 inches long, and uniform in
thickness all the way up. On April 25th, 1880, I gathered
a similar one in Great Hales Wood which was 11 inches long,
and three-quarters of an inch broad, but quite thin. Another
on April 16th last was 6 inches long, split and curled right
round (down and up again), and had 137 flowers in its umbel.
These very broadest ones nearly always appear just at the
end of the season; and they have a tendency to twist right
round, sometimes splitting down their whole length by so
doing.40 The number of flowers on these fasciated stalks
seems to have hardly any limit, but depends a good deal on
the extent to which the stalk is flattened. Thus the smaller
ones bear 20, 30, or perhaps 40 flowers; the medium ones
50, 60, and even 100 or over, as I have counted comparatively
small ones which have yielded 55, 83, and 96, while the very
largest bear sometimes, I am sure, quite 200 blossoms. Of
course these flowers that are so clustered together are not
of large size. In the very largest umbels there are many
buds which never open, or only imperfectly. With these
flat-stalked ones, too, the shape of the umbel entirely
changes. The flowers hang over thickly on all sides or
stand upright as best they can, instead of having a regular
order—hanging over on one side only.
On a few occasions I have met with these broad-stalked
specimens growing under thin cover, but when they occur I re-
gard them as due almost always to stimulation. Occasionally
specimens may be met with in which the peduncle suddenly
turns aside, and then growing up again for two inches or so,
bears the umbel; but, out of the bend, grow several pedicels
and often a green leaf. On one occasion only have I met with
what I have called, when speaking of the Cowslip, a "double-
umbel." Another variety, by no means rare, which occurs
40 Prof. Boulger has suggested that this twisting and consequent splitting
of fasciated stalks may be due to the circumnutation of the umbel.