Pleasures of Crocus
Reproduced from an article by the late Charlie Challenger
From The New Zealand
Garden Journal (Journal of the Royal New Zealand Institute of Horticulture),
Vol. 1, No. 1, March 1996, pp. 12-17.
One of the activities
of the RNZIH has been to assemble a list of New Zealand Plant Collections,
which collates information on people and institutions who hold collections
of particular groups of plants. Based on the scheme run by the English
National Council for the Conservation of Plants and Gardens, it
is intended to ensure that garden plants and threatened New Zealand
plants are not lost but retained in cultivation for future use.
My personal interest
in crocus goes back nearly fifty years, when I bought a range of
species from Ralph Cusack, then well known as a specialist in bulbs.
I was living in rather comfortless digs, and decided that crocus
in pots could improve my surroundings. In due course they all flowered
in the window of my bed-sit. The range of bulb coats, flower seasons,
flower structures and colours revealed by those pots was fascinating
and I was hooked! My literary mentor was E. A. Bowles, for his book
"Crocus and Colchicum" and the chapters on crocus in "My Garden
in Spring", the first volume of his trilogy, stirred even greater
enthusiasm. Bowles was capable of inspiring as well as instructing,
and although his style reads somewhat flowery today, he stimulated
as many people then as Christopher Lloyd does today.
It was many years before
I really got to grips with crocus, although my interest in them
never abated. Shortly after I came to New Zealand in 1956 I was
stimulated by Jean Foweraker, and her garden at Cashmere on the
hills above Christchurch was a plantsman's paradise. In particular,
she had crocus species naturalised throughout the garden. When the
Canterbury now the New Zealand Alpine Garden Society
was founded in 1960, Jean was a regular exhibitor with her "basket
of cut flowers", rarely without its complement of crocus species.
Her monthly lists of "Plants in Flower" in the Society's Bulletin
further stimulated members with the value of crocus. Mary Evans,
another founder member of the Society, was another of those infected
by Jean Foweraker, and she later became totally absorbed by crocus.
When I retired in 1982,
my wife and I decided to revert to my old loves nursery work
and alpines and we established Kereru Nursery as a hobby
occupation. One of our first purchases was a wide range of crocus
species, imported from Potterton and Martin in England. We continued
importing them in quantity for several years, and this was the foundation
of our stock of crocuses at the nursery. More rarities originated
from the superb seed lists of Jim and Jenny Archibald, particularly
the newly-discovered species of crocus from Turkey. Our first offerings
of crocus at the nursery were six autumn flowering species in 1986,
and the numbers offered have continued to increase year by year
until, in our final catalogue we listed over 70 different species
and varieties. Obviously, we have continued the good work of spreading
numbers were also increased in a further, sad, way. Mary Evans knew
that she was dying, and before her death in 1991 I made arrangements
to transfer her crocus collection to us. She had been collecting
for many years, had world-wide contacts with crocus specialists,
and had collected in the field in Greece and Crete in 1973 and 1978
in fact one of the finest Crocus sieberi
ssp. sieberi forms we hold (Photo 2) was collected in Crete
by Mary. Our agreement with Mary, on accepting her collection and
amalgamating it with our own, was that we would maintain, expand,
and document our joint collection as part of the New Zealand Plant
Collections List. This article is the first public contribution
to that end.
My first task was to
verify Mary's collection unfortunately many of the labels
had become fragile and broken, with critical parts of the name missing.
Mary's documentation was excellent, so with its aid, and the keys
and descriptions in Brian Mathew's monograph, "The Crocus" (Batsford,
1980), I have almost completed this task.
there are still about 80 batches awaiting final identification,
most appear to be only duplicates. I do not think there are any
more significant additions to be made to the total list of species
and sub-species held.
The other generous contribution
I must acknowledge here is the gift by Mrs Betty Laurenson of the
beautiful plates from George Maw's magnificent "A Monograph of the
genus Crocus" (Dulau, 1886). Although Brian Mathew's book is invaluable,
the plates, being produced by techniques which involve screening
and multicolour printing, are less clear than Maw's engraved plates
where fine detail is concerned. The detail of stigma and stamens,
corm coats, and leaf cross-sections in particular all of
which are essential in identification is better in Maw's
plates than Mathew's, even though in some cases they were made from
the same drawings. Nowhere is the value of "Maw" shown more clearly
than in the detail of corm coats. Almost all crocus species have
characteristic coats, and some of them C. laevigatus
for example are so distinct that they cannot be mistaken
for anything else. In others, although different, they are less
clearly differentiated, particularly when you haven't "Got your
eye in", Brian Mathew's word pictures are very accurate and precise,
but it does take time to grasp his precision of words. To him, the
differences between "membranous" and "papery", or "coarsely reticulated"
and "very coarsely reticulated" are quite clear; he has handled
thousands of bulbs. You have to learn the precision of his language.
But whilst you are doing so, one picture with the clarity
of Maw is worth a thousand words. Maw's book is a very expensive
rarity, so Betty Laurenson's gift was of real value, both in itself,
as well as for verifying identifications.
of the rare species held by Mary Evans were present only as single
specimens, but in almost all cases, corm numbers have been bulked
markedly since 1991. Whilst crocus sometimes may be bulbs of dry
and barren landscapes, they do respond to loving kindness, and in
particular careful use of fertiliser gives them a real zest for
life, multiplying much more freely. Today, the collection is in
good heart, accurate, and well documented. Mary Evans would be pleased.
So what is it that stirs
the collector to cosset his love? As Shakespeare said, "Custom cannot
cloy her infinite variety" even though he was writing of a different
sort of love! It is certainly not a case of "A crocus is a crocus
is a crocus" for their variety is well, not quite infinite,
but certainly very wide. The crocus genus is widely distributed
in the northern hemisphere, extending from 10 degrees west, in Portugal
and North Africa, to 55 degrees east, with odd species scattered
as far east as the Ala Tau Mountains in Western China. The majority
of species occur in the Balkans and particularly Turkey, where many
new species have been collected since the 1950s. Northwards they
extend as far as Krakow in S. Poland, and southwards into southern
Jordan and Iran. Although this distribution area is so wide, its
climate is largely a dry summer, winter rainfall regime, which makes
crocus so suitable for cultivation in eastern and central-southern
New Zealand. Nevertheless, not all crocus species appreciate summer
dry conditions, particularly those from open woodland habitats.
Crocus banaticus, C. scharojanii, the unpronounceable
C. cvijicii, and C. nudiflorus are all examples
of plants which should not be dried out in summer.
the most obvious of the "infinite variations" is the broad division
into spring and autumn flowering species. In fact the season extends
from early February until late September, with the bulk of species
blooming in either March and April, or June till August. A few species
such as C. imperati and C. laevigatus have quite
prolonged seasons over the winter months if the weather is kind.
The earliest of all is
C. scharojanii, the only autumn flowering species with
yellow flowers, followed in late February by C. vallicola. This
creamy-white species, with yellow spots in the throat and purple
veins to the petals, has distinct petal tips. They narrow abruptly
and then extend into a sharp point the only crocus which
does so. In March there is a long succession of species in flower
including C. kotschyanus, C. banaticus, C. cancellatus,
C. hadriaticus, C. nudiflorus, and C. pulchellus and
the closely related C. speciosus. In April C. medius,
the beautiful pair, C. longiflorus and C. tournefortii,
C. serotinus and its sub-species, and C. goulimyi are
amongst many which can be relied on, whilst the yellow-throated,
white flowered C. ochroleucus draws the season to a close,
flowering through into May.
can start very early if the weather is mild. C. laevigatus
occurs in a wide range of forms, collected from its various habitats
in Greece, Crete and the Greek Islands. So flower colours and sizes
vary widely and so do the flowering seasons, from May till August.
C. imperati is much less variable, but its lavender-purple
flowers with purple striped, biscuit-coloured external petals, is
one of the joys of the winter months (Photo 2). True spring flowerers
start with C. sieberi and its forms, C. corsicus, C.
dalmaticus, the yellow flowered C. korolkowii and
C. gargaricus, and many others. Crocus tommasinianus
and its later-flowering forms, 'Whitewell Purple' and 'Ruby Giant',
together with the multi-coloured varieties of C. chrysanthus,
form the main body of flowering in many gardens. The season
comes to a close with the late-flowering varieties of C. vernus,
the mountain crocus of the European Alps. Although crocus do
not commonly interbreed, some hybrids exist, and the September-blooming
vernus variety, 'Harlem Gem', shows distinct biscuit colours
in its external petals, which originate from the genes of C.
colours are usually white, yellow, and various shades of purple.
There is considerable variation in detail though, with white, yellow
and purple throats, distinct white or yellow eyes, a multitude of
different stripes on the interior and exterior of the flower, and
different internal and external colours overall. All are important
in identification. True blue is generally lacking, but a few recently
discovered Turkish species, such as C. baytopiorum
and C. abantensis are close to being china-blue. Unfortunately
both are still uncommon in cultivation. The most brilliant blue,
in my opinion, is C. biflorus ssp. pulchricolor,
but not all forms are equally beautiful. This variability is characteristic
of crocus and occurs in most of their characters size, colour
(Photo 3), corm coat, and leaf width. It is important that identification
does not depend upon a single specimen. The variation in flower
size between species is considerable; some, such as cultivars of
C. speciosus, are up to 10cm across, whilst the smallest,
C. cambessedesii (Photo 4) and C. danfordiae,
are only 20-25mm across.
and stamens are markedly different in the various species and are
most important for identification. C. banaticus not only
has three long and three short petals it is the only species
with this character, and used to be called "C. iridiflorus"
as a result but also has a unique purple stigma (Photo 5).
It is very finely dissected, the basically triple divided stigma
of crocus overall being split into very many segments. Stigmas vary
from being triple with frilled tips (C. sieberi and C.
chrysanthus) 6-lobed (C. olivieri) (Photo 6), to finely
dissected (C. banaticus and C. graveolens). Incidentally,
C. graveolens is the only crocus with an unpleasant scent.
Stigma colours vary from
white through cream and yellow to bright orange and red, and the
purple of C. banaticus. Several species have considerable
decorative value due to the stigma colour. In C. medius
and C. nudiflorus the contrast of rich purple petals and
scarlet stigma is very striking, but that of the pure white petals
and scarlet stigma in C. niveus and C. cartwrightianus
albus have even greater punch. Stamens are usually yellow or
white, but in a few species such as C. hyemalis, and C.
biflorus ssp. melantherus (Photo 7) they are purplish
black. The well-known spring crocus, C. chrysanthus, frequently
has distinct black, backward-pointing "barbs" on the stamens (Photo
8). The colour of the filaments, on which the stamens are mounted,
is either yellow or white, but occasionally, as in C. pestalozzae,
there are characteristic black spots at their base. E. A. Bowles
likened them to specks of dirt dropped into the throat of the flower.
coats are tremendously varied, all the way from coconut matting
to egg-shells and tissue paper in appearance. A 10X magnification
hand lens is an essential tool in diagnosis. Without it, the fine
detail is much less obvious. If you "get your eye in" by examining
very distinct species such as the coarse coated C. angustifolius
(Photo 8) or C. cancellatus, and the papery C. ochroleucus
(Photo 9), you can then progress to separating, say, C.
longiflorus and C. medius, or C. imperati
and C. dalmaticus, in which the differences are much less
marked. All these species have fibrous coats, but with differences
in their reticulate or parallel nature, and the fineness of the
fibres. Others, like C. laevigatus, are quite
unmistakable. It has a hard coat like an egg shell, which splits
into triangular points at the base. Often, a group of species will
have similar coat characters. For example, C. chrysanthus, C.
biflorus, C. pestalozzae, C. speciosus and C. pulchellus
all have corm coats in which the coat at the base of the corm separates
into rings. The papery coats of C. ochroleucus
and C. kotschyanus can be very similar, but then distinction
is possible on corm shape. Both are flattened, but C. kotschyanus
is markedly irregular in shape. To many, this may be esoteric
trivia, but I can assure readers that to the bulb nurseryman it
is essential know how for his trade; there is ample scope for a
photo-atlas of corm coats in crocus, and I am progressing towards
it. Such is the incidental value of a crocus collection.
Leaves in crocus species
vary in number, width, venation, and shape, and when added to the
other elements of identification already discussed, can help to
confirm or deny an identification. The widest leaf of all is C.
vernus, which can be 8mm wide; many compete for the title of
being the narrowest, and C. fleischeri, C. pestalozzae,
and C. danfordiae, as examples, all have leaves narrower
than 1mm. Leaves are usually two-faced, with a distinct upper and
under surface. In all except C. scardicus and C. pellistericus
the upper surface has a pale stripe down the centre. The underside
has various grooves and veins, beautifully depicted in Maw's plates,
often characteristic of a species. The only species without them
are the various relatives of C. kotschyanus - vallicola, ochroleucus,
scharojani and karduchorum. In these, the leaf
is rather like an H girder on its side, so that upper and under
surfaces are similar. Not all species have leaves which emerge with
the flowers, and all the autumn-flowering species, except C.
ochroleucus and C. serotinus and its sub-species,
have naked flowers. Leaf length at flowering can be a feature of
So it can be appreciated
that to the crocus fiend, their very variety is a feature of interest
as much as anything else, and when coupled with their garden value
particularly if your garden is small they are very
desirable plants. Cultivation is not difficult, and only a few are
not good "doers". Some are slow to multiply vegetatively
the Cretan forms of C. sieberi, for example, multiply very
slowly compared with those from Greece. Seed raising is quite straightforward,
and in most species the ripe capsules appear above ground, looking
like fat matchsticks, between November and January. A few, such
as C. caspius and C. hadriaticus, ripen their
seeds just under the surface, and are often held in the un-opened
seed capsule for some time. Seed should be collected and sown immediately,
surfacing the pans with grit; flowering normally occurs in the third
year. Generally, the needs of crocus are limited. A friable well-drained
soil in a sunny spot, the occasional light dressing of tomato fertiliser,
moisture during their growth period, and particular attention to
the needs of woodland species mentioned earlier. In areas which
are damp during the dormant season it may be necessary to provide
overhead protection for species originating in dry arid regions.
Otherwise just enjoy!
A list of taxa held in
our collection is appended for interest. Those listed in brackets
are taxa not held, but known to science. Items marked * have been
introduced to science since Mathew's monograph was published in
(C. biflorus subsp. albocoronatus)*
C. biflorus subsp. adamii
C. biflorus subsp. alexandri
C. biflorus subsp. biflorus
(C. biflorus subsp. crewei)
C. biflorus subsp. isauricus
C. biflorus subsp. melantherus
(C. biflorus subsp. nubigena)
(C. biflorus subsp. pseudonubigena)
C. biflorus subsp. pulchricolor
(C. biflorus subsp. punctatus)
(C. biflorus subsp. stridii)
(C. biflorus subsp. tauri)
C. biflorus subsp. weldenii
C. cancellatus subsp. cancellatus
C. cancellatus subsp damascenus
C. cancellatus subsp. lycius
C. cancellatus subsp. mazziaricus
C. cancellatus subsp. pamphylicus
C. cartwrightianus 'albus'
C. chrysanthus cultivars:
C. 'Blue Bearl'
C. 'Cream Beauty'
C. 'Gypsy Girl'
C. 'Snow Bunting'
C. 'Zwanenburg Bronze'
(C. flavus subsp. disssectus)
C. flavus subsp. flavus
(C. x fritschii)
C. hadriaticus subsp. hadriaticus
(C. hadriaticus subsp. lilacinus)
C. hadriaticus subsp. parnassicus
(C. hermoneus subsp. hertnoneus)
(C. hermoneus subsp. palaestinus)
C. imperati subsp. imperati
C. imperati subsp. suaveolens
C. x jessopae
C. kotschyanus subsp. cappadocicus
(C. kotschyanus subsp. hakkariensis)
C. kotschyanus subsp. kotschyanus
C. kotschyananus subsp. kotschyanus var. leucopharynx
C. kotschyanus subsp. suworowianus
C. olivieri subsp. balansae
C. olivieri subsp. istanbulensis
C. olivieri subsp. olivieri
C. pallasii subsp. dispathaceus
(C. pallasii subsp. haussknechtii)
C. pallasii subsp. pallasii
C. pallasii subsp. turcicus
C. pestalozzae var. caeruleus
C. reticulatus subsp. hittiticus
C. reticulatus subsp. reticulatus
C. serotinus subsp. clusii
C. serotinus subsp. salzmannii
C. serotinus subsp. serontinus
C. sieberi subsp. atticus
(C. sieberi subsp. nivalis)
C. sieberi subsp. sieberi
C. sieberi subsp. sublimis var. tricolor
C. sieberi x C. veluchensis
(C. speciosus subsp. ilagazensis)
C. speciosus subsp. speciosus
C. speciosus subsp. xantholaimos
(C. x stellaris)
C. vernus subsp. albiflorus
C. vernus subsp. vernus
passed away September 2007. His
obituary was published in the New Zealand Garden Journal (Journal
of the RNZIH), Volume 10, Number 2, December 2007. pp. 24-25.
The Crocus collection
described in this article was transferred to Dr Melva
Philipson of Nelson who maintained it but passed away in 2015.
Some of the accepted species names have changed since the original publication in 1996. Several apparent errors in Challenger's original publications are:
- Crocus chrysanthus 'Blue Pearl' is the name of an accepted cultivar, but appears to be mispelt 'Blue Bearl'
- Crocus × jessopae is an orthographic variant of C. × jessoppiae
- Crocus kotschyananus subsp. kotschyanus var. leucopharynx does not appear to be a valid name
- Crocus pallasii subsp. turcicus should be C. pallasii subsp. turcinus
- Crocus serotinus subsp. serontinus should be C. serotinus subsp. serotinus, and some sources now elevate subspecies of C. serotinus to species rank
- Crocus sieberi subsp. sublimis var. tricolor should instead be C. sieberi subsp. sublimis 'Tricolor'
- Crocus versicolour should be Crocus versicolor.
resources on Crocus
Pages "the largest online resource for the genus Crocus"
Jacobsen, N.; van Scheepen,
J.; and Ørgaard, M. 1997. The Crocus chrysanthus
- biflorus cultivars. The New Plantsman, Vol. 4, Part
Kerndorff, H. and Pasche,
E. 1998. Miscellaneous Note 1: On the type locality of
Crocus boissieri (Iridaceae). The New Plantsman, Vol.
5, Part 1: 11-14.
Mathew, B. 1982. The
Crocus. Batsford, London.
Mathew, B. 1998. White
forms of Crocus serotinus subsp. salzmannii. The
New Plantsman, Vol. 5, Part 1: 10-11.
Pasche, E. and Kerndorff,
H. 1999. A new natural hybrid in the genus Crocus (Iridaceae).
The New Plantsman, Vol. 6, Part 1: 43-46.