The Orchid Society of Great Britain

spectacular. I personally find the
identification of Cattleya species quite
difficult, and there are also many cultivars
and forms of each species. I hope this guide
will help those similarly confused, but at
least (for judging teams) it is also a list of
what is now in the genus Cattleya.
Culture
Cattleyas are epiphytic, with velamen
covered roots (similar to Phalaenopsis) that
absorb and retain water.
Grow in a bark compost – a weight in the
bottom of a plastic pot helps stop them
overbalancing, but clay pots are often used
for this reason. Most people grow them in
plain fir bark, but I find mine grow well in a
50/50 mix of Sphagnum moss and Perlite. If
you are frequently in the greenhouse, you
can grow them on a large sheet of cork bark
or a suitable branch, watering or spraying
daily so that moss also grows on the bark.
They prefer ‘intermediate’ temperatures
(minimum 15°C at night, 20°C in the day in
the winter; maximum 30°C in the day in the
summer). Water well and feed alternate
weeks when growing in the summer, and
they can be allowed to dry out for a day
between watering. Water sparingly in the
winter. Light shade is all that is required in
the summer and no shade in the winter. You
will need to stake the taller growing Cattleya
canes (pseudobulbs) as they grow to keep
them upright, and the heavier flowered
hybrids may need to have their flowers
supported as well. The latter is done very
well by the Taiwanese growers who wrap
soft wire round the ovary and pedicel of the
flower, and support it in this manner on a
thin bamboo stake.
Cattleyas
Horticulturally we divide them into
unifoliate (subgenus Cattleya) and bifoliate
(subgenus Intermediae) cattleyas, depending
on whether they have one or two thick fleshy
leaves at the top of the cane. The bifoliate
cattleyas are mainly from Brazil. I refer the
reader to Cattleyas and their relatives by Carl
Withner for a review of the different
infrageneric classifications. Thousands of
artificial hybrids have been made.
Botanically, they have recently had a shake
up in nomenclature, and all the plants that
used to be Sophronitis and all the Laelia that
come from Brazil have been moved into
Cattleya. The genus Gurianthe, including G.
aurantiaca, G. bowringiana and G. skinneri,
which used to be Cattleya is still a separate
genus and has not been moved back
following the DNA studies on these plants.
Currently there are 110 species recognised,
but many are rare in cultivation. Over 600
synonyms, varieties and natural hybrids are
listed in the Kew Monocot List.
This pictorial guide lists all the species
currently in Cattleya with illustrations of
many of them. Also recorded, from the Kew
Monocot Checklist, is the publication in
which each plant was first described.
Withner’s books are the source of most of
the other information.
World Checklist of Monocotyledons. The
Board of Trustees of the Royal Botanic
Gardens, Kew. Published on the Internet;
http://www.kew.org/wcsp/monocots/
accessed 9/10.
Withner, Carl, L. The Cattleyas and their
Relatives. Vol. 1. The Cattleyas. Timber Press
1988
Withner, Carl, L. The Cattleyas and their
Relatives. Vol. 2. The Laelias. Timber Press
1990
OSGBJ 2010 (59), No. 4 • 231