LILIES - RHS Lily Group

or Cliftonii Group in gardening circles, is horticulturally distinct in that it flowers
noticeably earlier, in fact one of the earliest of all erythroniums, and in my
experience does not have the same propensity to produce stolons.
The unique pink E. revolutum is perhaps the most prolific species in Britain,
especially in the higher rainfall western side of the country. One can see large
drifts in many gardens ranging from the south-west (for example Knightshayes)
all the way up to north-western Scotland at Inverewe. As a wild plant it is also
widespread in a north-south direction at fairly low altitudes from Vancouver
Island to California, and it is very variable. The species is almost entirely
seed propagated so named variants are not clonal although some breed true
enough and have been given cultivar status. So, we have dark pink ones named
‘Johnsonii’ (this was originally described as a species) and other shades such
as ‘Knightshayes Pink’, ‘Pink Beauty’, ‘Rose Beauty’, etc. Species such as this
create a dilemma for those assessing the merits of a plant for the AGM. Should
the award be given to the entire species encompassing all its variations, even if
some might be less pleasing than others, or should only ‘the better’ variants be
acknowledged? There is no real answer but the matter can usually be resolved by
asking oneself: ‘would I throw out any form of E. revolutum on the grounds that
it was inferior?’ In this case I suspect that the answer from most people would be
a resounding ‘no way’! This question does not arise in the case of E. hendersonii,
another western American species which is more restricted in distribution in
southern Oregon and northern California. It varies only a little in the depth of
pale lavender-violet of its flowers which have a distinct dark violet eye in the
centre, a unique colour combination in the genus. As a result of this comparative
uniformity I am unaware of any named cultivars. As with E. revolutum there is
little tendency for the bulbs to produce offsets, so seeds are the only practical
method of propagation.
All the species mentioned so far are from western North America and, quite
frankly, that is where the most striking species occur. Of the remaining species
from that region one could mention a few other very desirable ones which are easy
to cultivate, notably E. oregonum. Although superficially similar to E. californicum
(mottled leaves and white flowers, usually with a zone of dark markings in the
centre) the two are distinct and a check on the width of the stamen filaments
will clarify any uncertainty: slender throughout their length in E. californicum but
wide and flattened at the base, tapering to the apex in E. oregonum. For many
years there has been in cultivation in Britain a variant known as “Sulphur form”, a
pleasing variation with pale sulphur-green flowers. Unfortunately the stock came
without an indication of provenance so I was intrigued to find it also in a garden
in Oregon and, on enquiring, was told that it was the form from Kelley Butte.
Only detailed field studies will shed further light as to whether any botanical
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