SYSTEMATIC BOTANY
Systematics research at Kew covers many taxonomic levels and
character types.
Cypripedium Morphology &
Molecules
Britain's sole surviving slipper orchid is probably its most
famous plant. The propagation and re-introduction of Cypripedium
calceolus by Kew was the inspiration for Dr Phillip
Cribb's account, The Genus Cypripedium, which has just
been published as the latest Botanical Magazine monograph. The
monograph provides an identification key and detailed account of
all 47 species. Each is illustrated with a fine line drawing by
Eleanor Catherine and, where possible, by a photograph of the
plant in its natural habitat, mostly taken by the author during
expeditions to the Americas and China. Details of cultivation are
also provided by Holger Perner, a well-known German slipper
orchid grower. Introductory chapters cover the history of the
genus, its morphology and anatomy, cytology, biology, ecology,
conservation, evolution, and classification. One chapter
chronicles the decline of the British plant and current attempts
to save it.
Kew is fortunate in having several species of Cypripedium
in its living collections and this has permitted Dr Tony Cox and
co-workers to compare a DNA analysis of the genus with taxonomies
based on morphological characters. Extant taxa seem to be
characterised by high degrees of morphological and DNA
divergence. This may be due to either long periods of isolation
or extinction of intermediate forms. While more detailed studies
are still needed, it appears that Eurasian yellow or red-flowered
species and North American yellow-flowered species form two
natural groups. The multi-flowered species (C. irapeanum
and C. californicum) appear to represent the earliest
diverging lines and in many respects share similarities with
their sister genus Selenipedium.
Cypripedium tibeticum.
Contact: Dr Phillip Cribb (0181-332 5245)
Systematics Conferences
The breadth of systematics research undertaken at Kew was evident
from the number of papers presented at major meetings this summer
that had Kew involvement: 24 papers at 'Systematics' in Oxford
(many by postgraduate students), 15 at the AIBS meetings in
Montreal, and four at the SEB meetings in Boulder. Many papers
related to the combination of different data matrices. For
example, at 'Advances in Plant Molecular Systematics' in Glasgow,
Dr Mark Chase gave an invited paper written with Dr Renee Grayer
and others on the combination of molecular and phytochemical
data. Mark also organised a symposium on large data sets at the
Oxford meeting (where Kew's Director gave the opening address)
and was a co-author, with Dr Alec Pridgeon, on a paper on
Orchidinae presented at Glasgow by Dr Richard Bateman (RBG
Edinburgh)
Contact: Dr. Mark Chase (0181-332 5364)
Also this summer, Dr Dick Brummitt attended a meeting of the
committee for the Species Plantarum Project, of which he is
convener, at the California Academy of Sciences. The project aims
to produce a World Flora giving all basic taxonomic data down to
species and infraspecific levels. The committee accepted the
offer by the Australian Biological Resources Study, which
publishes Flora of Australia, to edit and publish the proposed
Species Plantarum in a similar format. Two smallish sample family
treatments (Irvingiaceae and Morinaceae) were presented for
publication and both hard copy and electronic versions are
envisaged. The project is obviously very ambitious and long-term,
but unless a start is made, a complete synthesis of taxonomic
information on the higher plants of the world will never be
achieved.
Contact: Dr Dick Brummitt (0181-332 5247)
Pollen Development in Asparagoid Lilies
Recently published research on the lily group (Lilianae) by Drs
Paula Rudall, Carol Furness, Mike Fay and Mark Chase has revealed
close correlation between certain pollen characters and the
generic relationships indicated by rbcL sequence data analysis.
This underpins current concepts of the relationships of these
plants and in turn provides new insights into the evolution of
pollen aperture types.
Meiosis leading to pollen development (microsporogenesis)
involves either almost simultaneous nuclear divisions, without
intermediate cell wall formation, to produce tetrahedral tetrads,
or successive nuclear divisions, with wall formation after each,
to produce tetragonal tetrads. Although most monocotyledons have
successive microsporogenesis, simultaneous microsporogenesis is
characteristic of early-branching taxa of Asparagales (including
Iridaceae and Asphodelaceae), with a reversal back to the
successive type in a large group of later-branching taxa
(including Alliaceae and Hyacinthaceae). Most Asparagales have
monosulcate pollen, but one group (Phormiaceae plus some allied
taxa, such as the European genus Simethis and the Australian
genus Johnsonia) have a forked sulcus (trichotomosulcate pollen),
always associated with simultaneous microsporogenesis.
Paradisea liliastrum:
tetragonal tetrad. Differential interference contrast.
Contact: Dr Paula Rudall (0181-322 5331)
The Genera of Araceae
The publication in September of The Genera of Araceae is the
culmination of an idea first broached in 1980 during the first
international workshop on Araceae systematics held at the Marie
Selby Botanical Garden, Florida. Dr Simon Mayo began a manuscript
with Dr Michael Madison (organiser of the conference) but the
project really developed in 1987 when he, Peter Boyce and Josef
Bogner (Munich Botanic Garden) resolved to tackle the task anew,
under the encouragement of Prof. Gren Lucas (then Keeper of the
Kew Herbarium). Eleanor Catherine, the artist, completed the team
later, but many other colleagues from 36 institutions around the
world have also contributed in various ways, such as providing
material for drawing, supplying critical unpublished data or
reviewing chapters.
The final form of the 370 page work was essentially inspired by
Uhl & Dransfield's Genera Palmarum. A general part gives
condensed treatments of the major character fields and includes
chapters on anatomy by Prof. J.C. French and chemistry by Prof.
R. Hegnauer as well as other subjects of interest such as
phylogeny, fossils, uses and conservation. In the taxonomic part,
each of the 105 recognised genera is described and illustrated
with one or more original line drawings. A range map is provided
for each genus and 96 genera are shown as colour photos; the
latter are selected to show especially the shapes and colours of
the inflorescences and infructescences. Genera of Araceae is also
available as a CD.
Above: Biarum
ditschianum, a
recently discovered and very distinctive species from limestone
crevices and chimneys in southern Turkey, flowering in Kew's
Alpine Unit.
Contact: Dr Simon Mayo (0181-332 5213)
Economic Araceae
An 'Alice' database of economic uses of Araceae has been compiled
by Kerry Taylor (placement student, University of the West of
England) and Peter Boyce. Over 800 aroid species have economic or
ethnobotanical importance but the information has never been
brought together. Data were assembled from scanning the
literature, Index Kewensis, Kew's herbarium collection of ca
30,000 sheets, the Internet and letters or emails from colleagues
around the world, particularly members of the International Aroid
Society. A checkist of economic and ethnobotanically important
Araceae will be published and the information made available on
the Internet.
Contact: Peter Boyce (0181-332 5207)
Araceae Chemistry
Two aspects of Kew's work on Araceae chemistry have been
published recently. Firstly, a survey of the family for
alkaloidal sugar mimics revealed they were largely restricted to
Aglaonemateae and Nephthytideae, supporting molecular data
indicating a relationship between these tribes. Secondly,
analysis of the inflorescence odours of several Amorphophallus
species (including A. titanum which flowered last year at Kew),
in collaboration with the independent expert Wilbert
Hetterscheid, revealed foul-smelling dimethylsulphides in groups
of related species. The odours of other species were quite
different; for example, the cheese-smelling A. elatus produced
almost pure isocaproic acid
Above: Geoffrey Kite collecting the inflorescence
odour of Amorphophallus
henryi growing in
Kew's Science Support Unit.
Contact: Dr Geoffrey Kite (0181-332 5368)
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