Contents of the Winter 2010 Northants News
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Flowering Report - Astrophytums Roland Tebbenham |
I
mentioned in an earlier article that I had maintained a weekly flowering diary
during 2009. This is my first report based on those data and I have selected a
popular genus – Astrophytum.
These species are easy to grow from seed and have quite large, bright flowers. I
have fifteen plants, ten of which flowered during 2009. There were flowers to
enjoy during sixteen of the twenty-one weeks from April 20th to July
7th inclusive. They do need good light to flower well, in common with
many cacti, whether grown on a sunny window sill or in a conservatory or
greenhouse.
The
New Cactus Lexicon lists six species: Astrophytum
asterias,
capricorne, caput-medusae, coahuilense, myriostigma and
ornatum.
There are also many hybrids and cultivars available, some the result of
extensive hybridisation and selection in Japan. I offer you a selection worth
considering as much for their appearance out of flower as when ‘paying the
rent’ during early summer.
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Astrophytum
asterias
which, when well grown, should be quite flat, with woolly, spineless areoles.
The petals are yellow, sometimes flushed pink, up to 4cm diameter. It is scarce
in the wild and requires gritty compost and a 5C minimum winter temperature to
do well. The species is used widely for hybridising and the cultivated form
‘Superkabuto’ is found with many different markings. |
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Astrophytum
capricorne is
globose to short columnar with long, flexible curved spines that vary in colour
from black, brown, yellow to nearly white. My young plant has tufts of shorter
spines. It is a slow grower and requires an alkaline soil with added limestone
reflecting its rocky habitat. Flowers are lemon to golden yellow with red
centres. Some variants are sold as varieties; my Astrophytum
capricorne ‘v. aureum’ has
nice, curving longer spines and also flowers well. |
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Astrophytum
myriostigma is
a familiar, widespread, spineless attractive plant, known as ‘The Bishop’s
Cap’ or ‘Bishop’s Mitre’, referring to the normal five-ribbed form. The
rib count varies from three up to eight, though many revert to five; also there
is a ‘nudum’ form lacking the epidermal flecks. The plants are globular,
becoming columnar with age, though they can become corky near the base. Flowers
are light yellow with no red centre and generally smaller than those of other
species. The other three species are not in my greenhouse: Astrophytum
coahuilense
is similar to A
myriostigma
but with very dense flecking and red-throated flowers, the slow-growing Astrophytum
ornatum
and the weird, recently described, long-tubercled Astrophytum
caput-medusae.
If you have photographs of them in flower then send some images to Editor Trev. |
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I
now turn to hybrids; many are available and you can select those that appeal to
you; but do remember that plants from the same nominal cross can vary
considerably. The hybrid names are written as ‘female parent’ X ‘male
parent’. To be contentious – maybe we need to move to registered ‘grex’
names for particular results of primary crosses as in the orchid world, with
named cultivars defined within each grex? My plant of A asterias X myriostigma has very woolly areoles, but few epidermal flecks. The flowers are large and yellow, flushed pink. |
My A
capricorne X asterias
has light yellow flowers with distinct deep red centres. Though A
asterias
is used in a lot of hybrids, there are other combinations. My specimen of A.
myriostigma X capricorne
is intermediate between its parents with many body flecks, wispy spines and
intermediate-sized yellow flowers with red centres. I consider it to be a
handsome plant! I am sure that you can find other examples with particular
features to enhance your collection.
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Finally
I highlight two named cultivars, both widely available in the horticultural
trade: A ‘Onzuka’ and A ‘Ortyki’. The former is a variant of A
myriostigma
created in Japan in the late 1970s with four ribs and very dense flecks. It has
the typical light cream to lemon-yellow flowers of the species. The latter
cultivar is clearly related to A asterias, but I cannot find where it
originated. A little research told me that ‘ortyki’ means, in Greek,
‘quail’ written as ortuki.
Maybe it refers to the plant’s superficial resemblance to the bird? My plant
flowered a little later than the others highlighted in this piece; it was worth
waiting for its golden petals and deep red centre similar to A
asterias.
If any reader knows more about the source of this cutivar, please do let me
know. Maybe you already grow Astrophytums, if not I recommend you should acquire
some. If you have some species, then maybe selected hybrids and cultivars could
add extra dimensions to your display. Either way they are attractive plants that
do not grow too quickly. I plan to report more from my flowering diary in future
issues of Northants News, Editor permitting of course! Roland
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References
‘The
New Cactus Lexicon’ ed David Hunt ISBN: 0 9538134 4 4
‘Ariocarpus
et cetera’ by John Pilbeam & Bill Weightman ISBN: 0 902099 78 7
