HEBE
BOOK REVIEWS
Gardening
with Hebes
By Chris and Valerie
Wheeler, Guild of Master Craftsman Publications, United Kingdom,
2002, ISBN 1 86108 2916, paperback, 149 pages 210 × 275 mm, $59.95.
Review by Tony Hayter
(aj.me.hayter@boltblue.com)
The Hebe Society
(UK)
Reproduced with
his permission from
The New Zealand Garden Journal (Journal of the Royal New Zealand
Institute of Horticulture), Vol. 5, No. 2, December 2002, p. 20.
Chris and Valerie Wheeler
founded Siskin Plants, a nursery specialising in dwarf plants, in
the aftermath of the Great Storm of 1987. They hold the National
Collection of Dwarf Hebes. The business has recently been sold,
but they will continue to hold the national collection, and sell
a wide range of dwarf hebes by mail order.
The introduction to this
book states that its aim is to give ideas on how to enhance the
garden with hebes, and practical advice on growing and maintaining
hebes. Hebe is a diverse genus, with a hebe for most situations
in the garden. Their popularity has steadily increased over the
last 20 to 30 years, which has led to an increased interest in breeding
hebe hybrids, and a correspondingly large number of new introductions.
Opposite the introduction there is a full-page photo of a single
raceme of Hebe 'Nicola's Blush'. This stunning photo is
the first of many. In fact, this book is full of excellent photos,
beautifully produced and full of practical information useful for
anyone who grows hebes.
In Chapter 1, "Origins
and Characteristics", Chris and Valerie give an introduction to
New Zealand and its plants, of which Hebe is the largest
genus. They state that hebes are found also in Australia, although
I think they are referring to parahebes. They then examine New Zealand's
wide range of habitats, and show that hebes fit into all of these.
The suitability of hebes for growing in the northern hemisphere
is discussed, and is followed by notes on the breeding of new hebe
hybrids. The authors describe the various forms of hebe flowers,
hebe growth habits, leaves, stems, winter colour and hardiness.
Again these characteristics are shown in colour photos.
In Chapter 2, "Using
Hebe in the Border", the authors move into the garden. They start
the chapter with two large colour photos, Hebe 'Midsummer
Beauty' and Hebe salicifolia, which certainly grab your
attention. They then discuss the use of hebes as an evergreen backbone
to borders, especially their importance in winter, when all herbaceous
plants have died down. The wide range of hebe leaf colour is important,
and here the more highly coloured new growth is mentioned. The authors
examine hebes in new borders, the wide variation in size and its
importance, uses for low-growing hebes, and the use of hebes as
a backdrop for other plants, statues or containers. The chapter
ends with the authors showing how to combine hebes with other plants,
and two suggested planting schemes. Both schemes are illustrated
with double page, colour sketches.
Chapter 3 deals with
hebes for rock gardens and raised beds. Their evergreen foliage
is again used as a green background, and a contrast with herbaceous
alpines. After covering the cultivation of hebes in rock gardens
and raised beds, they suggest two planting schemes, both illustrated
with double page colour sketches. In Chapter 4, Chris and Valerie
demonstrate which hebes to use for ground cover, as well as their
cultivation.
In Chapter 5, the authors
compose a symphony of hebes. They look at the points you should
consider when planning a bed consisting of hebes alone. These include
contrast of foliage, and the scale and shape of the planting. They
end the chapter with examples, using tables of hebes, and in double
page, annotated, colour drawings.
Chapter 6 is about hebes
in containers. Container gardening is increasingly popular, with
many variations possible in size and positioning. The smaller hebes
are best for containers, the larger ones quickly outgrowing the
space available. The authors consider the types of container available,
the choice of hebes for foliage and flowering, the use of frost
tender hebes, hebes in combination with other plants, and lastly
hebes in sinks. These themes are demonstrated with three double-page,
annotated, colour drawings.
In Chapter 7, Chris and
Valerie cover all aspects of the cultivation of hebe hedges, using
large, medium and small hebes. The hedges are nicely illustrated
with colour photographs. Indeed, there is a full-page illustration
of one of the best hebes, Hebe rigidula, which grows very
well in my garden.
Chapter 8 covers hebes
as standards, a topic on which there have been several articles
in Hebe News. The techniques for creating standards are
illustrated for Hebe rigidula, although larger and smaller
hebes can also be grown as standards. The authors also describe
topiary for hebes, i.e., growing them to a specific shape, such
as a sphere, cone, or as a ball on a stem.
Chapter 9 is about the
cultivation of hebes, and is one of the most useful chapters in
the whole book. The authors deal with topics such as the best position
to plant hebes, how to plant them in the border and in a container,
watering and feeding, and pruning and propagation. The chapter ends
with a troubleshooting section, the effects of drought, wind scorch,
frost damage, downy mildew and aphids. Again the excellent colour
photos show you which problem you have, and the text tells you how
to deal with it.
The last and largest
chapter describes one hundred hebes, many with an accompanying photo.
The authors note particularly successful plant combinations with
each hebe.
Both Douglas Chalk and
Graham Hutchins have written books on hebes. These have a strong
botanical flavour, and are more useful to the hebe aficionado. The
International Register of Hebe Cultivars by Lawrie Metcalf
is a very useful exploration of old hebe cultivars, but is not a
guide to cultivating hebes. If you wish to learn more about growing
hebes, and how to use them in your garden, this is the book for
you.
A version of this review
appeared in Hebe News 17(4): 23-25.
Available
from Touchwood Books
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Hebes
and Parahebes
By Douglas Chalk, 152
pages.
Reviewed by Tony Hayter
(aj.me.hayter@boltblue.com)
The Hebe Society
(UK)
Reproduced with
his permission from
Hebe News, Volume 16, No. 2, pages 25-28.
Douglas Chalk was a founder
member and Vice President of the Hebe Society . Hebes and Parahebes
was the first book on hebes. It was published in 1988 in New Zealand,
the United Kingdom, and the United States, and is now out of print.
Douglas's book appropriately
enough has a foreword by Lawrie Metcalf. Chapter 1 has a brief introduction
to New Zealand and a comparison of growing conditions in New Zealand,
North America and the British Isles. In chapter 2 Douglas describes
the change of name from Veronica to Hebe, the
differences between Veronica and Hebe, and the
splitting of the sub-shrubby genus of Parahebe from both
Veronica and Hebe. Chapter 3 explores the features
of hebes: the variety of size, shape and colour of leaves, leaf
bud sinus, colour of stems, times of flowering, colour of flowers,
types of inflorescences. Lastly there is a table of 46 hebes and
2 parahebes with their sizes, flower colour, leaf colour and
times of flowering. The growing of hebes and parahebes is described
in chapter 4. Here Douglas considers soil types, frost, wind, preparation
for planting, shelter belts, pruning, and lastly pests and diseases.
In chapter 5 he discusses the propagation of hebes and parahebes
from seed, cuttings and layering. Chapter 6 is devoted to hebe nomenclature.
Douglas in chapter 7 advises on which hebes and parahebes to grow
in a variety of situations: troughs, ground cover, borders, coastal
areas, and hedges.
In chapter 8, the largest
chapter, Douglas describes nearly 300 species, varieties and cultivars
of Hebe. The description is usually a paragraph or two.
Sixty hebes are illustrated in colour, thirty as line drawings.
Chapter 9 discusses the Chionohebe species and chapter 10 the
Parahebe species and cultivars.
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Hebes
Here and There
By Graham Hutchins, 320
pages.
Reviewed by Tony Hayter
(aj.me.hayter@boltblue.com)
The Hebe Society
(UK)
Reproduced with
his permission from
Hebe News, Volume 16, No. 2, pages 25-28.
Graham Hutchins, founder
member and Chairman of the Hebe Society, wrote Hebes Here and
There, illustrated by Patricia K R Davies. It was privately
published by them in 1997, and is available from the authors.
Hebes Here and There
starts with maps of New Zealand, a preface by our President, Chris
Brickell, and an introduction detailing the history of Graham's
involvement with hebes. In chapter 1 he introduces the geography
of New Zealand, and gives an introduction to naming hebes. All aspects
of the cultivation of hebes, hebes recommended for special situations
and purposes, and time of flowering are described in chapter 2.
Graham in chapter 3 shows us how to study and describe hebes, with
the aid of many useful drawings. Chapter 4 describes the identification
of hebes: firstly by assigning them to one of six groups, based
on presence or absence of sinus, and size of leaf, secondly by matching
to one of 217 drawings of leaf outlines. In chapter 5 Graham describes
170 Hebe species, subspecies and varieties. A detailed
description of each hebe is given. In chapter 6 he describes 115
Hebe cultivars.
Available
from Touchwood Books
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International
Register of Hebe Cultivars
L. J. Metcalf, 232 pages,
ISBN 0-9597756-4-1.
Reviewed by Tony Hayter
(aj.me.hayter@boltblue.com)
The Hebe Society
(UK)
Reproduced with
his permission from
Hebe News, Volume 16, No. 2, pages 25-28.
Lawrie Metcalf is the
International Registrar for Hebe. In the introduction he
describes the frustrations of trying to obtain information for hebe
cultivars that have been raised outside New Zealand, where information
was either limited, or in some cases lost altogether. There is a
brief account of the current state of research on the limits of
the genus. This is followed by a brief history of the introduction
of hebes outside New Zealand, and the naming of the genus. Also
mentioned is that the Hebe genus can be divided into 10
informal groups (although hybrids between hebes in differing groups
can cause problems in assigning them to a group).
In the first section
Phil Garnock-Jones describes the origins and evolution of Hebe.
Hebe with Parahebe, Chionohebe and Heliohebe*
forms the Hebe complex, which occupies many regions and
habitats in New Zealand. By studying a range of characteristics
of the complex, including the DNA sequences, Garnock-Jones and fellow
researchers are able to infer their evolutionary history. (*The
paniculate group of hebes, eg Hebe hulkeana.)
Hebe and allies
probably evolved from the northern hemisphere Veronica
complex. The nearest relative is the Australian genus Derwentia,
which includes digger's speedwell. A significant evolutionary advance
was the closed terminal bud of Hebe, which protected the
growing tip from frost and allowed a shrubby habit.
Hebe and its
relatives seem to have arrived in New Zealand about 10-15 million
years ago, the parent having crossed the Tasman Sea. The Heliohebe
hulkeana group split early from Hebe. Chionohebe and
Parahebe are closely related and there may be some reclassification
necessary. Research is continuing, and a fully illustrated field
guide to Hebe is to be published in 2002.
The second section, by
Peter Heenan, relates the history of Hebe as a garden plant.
The first explorers of New Zealand sent plants to the leading botanic
gardens of Europe. After 1840 the explorations of resident botanists
(eg Colenso and Kirk) fostered the founding of domestic botanic
gardens and a horticulture trade.
Many hebes were sent
as seed to Britain in the 19th century. In particular
Isaac Anderson-Henry of Edinburgh did much to popularise Hebe.
By the end of the century there were about 40 species in cultivation.
At the beginning of the 20th century Dorrien-Smith sent
Wardian cases of New Zealand plants to Britain, including new introductions
such as Hebe buchananii and Hebe bollonsii. This
process has continued with botanists including Graham Hutchins collecting
and introducing hebes.
The first named hebe
hybrid was Hebe 'Rosea', raised in 1845 from open pollinated
seed of Hebe speciosa; indeed this species was a parent
in many 19th century hybrids. Anderson-Henry used it
in the first artificial hybrid, crossing with Hebe stricta
to give Hebe 'Andersonii'. Hebe breeding programs
have continued on and off in Britain and New Zealand, with Jack
Hobbs of Auckland raising the Wiri series in the 1980s.
The history of hebe cultivars
has been plagued by poorly described, poorly documented plants,
with no herbarium specimens. Indeed even botanic gardens had difficulty
with their species; it turned out that plants of Hebe cupressoides
were the hybrid Hebe 'Azurea'. Since 1840 there has
been a steady increase in the number of hebe cultivars introduced
and named.
The variety of habit,
leaf size, leaf shape, flowering time and habitat requirements of
hebes enables them to be grown in a variety of garden situations.
Training Hebe speciosa as a standard was accomplished as
early as 1847. Their use as pot plants was noted in 1887, and in
1990 over 2.5 million hebes were grown as pot plants in Denmark.
Much attention has been paid to the frost tenderness of hebes, the
early literature discussing it in 1880, with research continuing
to the present.
In the third section
of the register Lawrie lists over 1000 hebe cultivars. What makes
this particularly useful is inclusion of synonyms. Thus we are told
that Hebe 'Autumn Beauty' of New Zealand nurseries
is the same as Britain's Hebe 'Autumn Glory', and
that Hebe 'Knightshayes' is a synonym for Hebe 'Caledonia'.
The fourth section is a similar listing for Heliohebe.
Following this are 16 good colour plants of hebes.
The fifth and largest
section is the 'Biographical List of Hebe Cultivars'. This contains
descriptions, and the source for the descriptions, of nearly 700 hebes.
For example Lawrie gives us five references for Hebe 'Andersonii',
and follows with a brief description, and historical notes. The
length of the entries vary, the largest occupying a page, smaller
ones just one line; and depends on the amount of information available
to him. The sixth section lists the biographical data for the heliohebes.
This well produced book
will appeal to all members having an interest in the origins of
their hebes. The books by Douglas Chalk and Graham Hutchins are
largely horticultural, with a leavening of botany, so the International
Register of Hebe Cultivars will complement them well.
Available from:
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International
Register of Hebe Cultivars
L. J. Metcalf, 232 pages,
ISBN 0-9597756-4-1.
Review by Bob Edwards
Commercial
Horticulture
Reproduced with his permission from
Commercial Horticulture, July 2001, pages 50-51.
The first Hebe
cultivar register, a 15-year of labour of love and painstaking research
by native plantsman Lawrie Metcalf, is an extremely valuable reference
to over 800 cultivars produced from the 100 or so species, mostly
endemic to New Zealand.
It is not complete, says
Lawrie, noting the first species to be described was Hebe magellanica
(South America) and that many hybrids and selections may have existed
in France but have yet to be unearthed and he suspects a revision
may be necessary in the future.
He welcomes additional
information and can be contacted at Greenwood, 179 Westdale Rd,
RD1, Richmond, Nelson.
The 232-page book also
contains two general chapters: Hebe: Origins and Evolution
by Professor Phil Garnock-Jones (Victoria University, Wellington),
a useful modern background to the genus; and A History of Hebe
as a Garden Plant by Dr Peter Heenan (Landcare Research, Lincoln),
a thoroughly researched guide to 150 years of Hebe gardening
and trade history.
Both have excellent references
that will be invaluable for students undertaking further work.
Extensive
indexes and cultivar descriptions
Over 135 pages of cultivars
and hybrids are listed together with their origins, descriptions
(where available), references to journals, catalogues, indexes,
papers where these have been found, synonyms, incorrect and invalid
names, and in many cases additional notes and interpretation by
the genera's International Registrar, the author.
A separate alphabetical
listing with cross references will assist readers through the maze
and the 16 colour photos will make identification of some modern
releases easier.
The final chapter, a
4-page Heliohebe list, is a bonus.
To those who tinker with
names we suggest you read the entry for Hebe Eveline (introduced
c.1893) and the headache this has caused. It has also been listed
as Evelyn, Gauntlettii, Evalina, Gauntlette, speciosa Pink, Pink
Payne, Rainers Beauty, Pink Lord, speciosa Gauntlettii, Pink and
Pink Pearl. Emerald Gem and others have suffered a similar fate.
To those who select,
breed and release new Hebe cultivars: have them described
properly, registered and written up to make the Registrar's job
easier and ensure correct, detailed information is published quickly.
Growers and retailers
will find this Royal New Zealand Institute of Horticulture publication
a valuable reference. It is the start to getting the correct cultivar
names in circulation once and for all and a major effort is needed
as the muddle existing in the trade and in gardens is considerable.
Spelling also needs to
be tidied. Hebe Margret is often written incorrectly as
Margaret. The Registrar has not accepted the name Mary Antoinette
for the blue hebe released by Annton Nurseries (Cambridge) as it's
too similar to Marie Antoinette, a variety written up in The Floral
World and Garden Guide in 1874, 112 years earlier.
The number of lost cultivars
and hybrids is of major concern.
As there is no repository
for Hebe cultivars and hybrids and as many of the hybrids
now in circulation here and overseas are likely to go out of production
due to rapidly changing trends and fashions, a pictorial reference
is now urgent.
The International Register
of Hebe Cultivars is an impressive work, a must for everyone
interested in the genus and an excellent companion to Douglas Chalk's
Hebes and Parahebes, Lawrie's bibles and Flora of New Zealand volumes
that contain additional information. Highly recommended.
Available from:
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Hebes,
A Guide to Species, Hybrids, and Allied Genera
By Lawrie Metcalf, published
by Timber Press Inc, The Haseltine Building, 133 SW Second Avenue,
Suite 450, Portland, Oregon, USA, 2006, 260 pages, ISBN-13: 978-0-
88192-773-3, ISBN-10: 0-88192-773-2.
Review by Tony Hayter
(aj.me.hayter@boltblue.com)
The Hebe Society
(UK)
Reproduced with
his permission from The New Zealand Garden Journal (Journal of
the Royal New Zealand Institute of Horticulture), Vol. 9, No. 2,
December 2006, p. 26-27.
I bought my first hebe
in 1980, and my interest soon spread to other New Zealand plants.
So I soon bought a second hand copy of Lawrie Metcalf's The Cultivation
of New Zealand Trees and Shrubs (republished in 2000 as New
Zealand Trees and Shrubs). This has been a constant companion,
with its mixture of horticulture and botany, presented in a clear,
thoughtful and comprehensive way. There was the pleasure of anticipation
when I heard that Lawrie was proposing to write a book on growing
hebes, the first by a New Zealander.
The book describes more
than 365 species, subspecies, varieties and hybrids of Hebe
and related species. It is illustrated with 135 colour photographs
and 17 line drawings.
In Chapter 1, Hebes in
New Zealand, Lawrie sets the scene. He points out the premier place
that hebes have in their native land, both in the gardens and countryside.
They even have their own society. Hebe is the largest genus
of flowering plants in New Zealand, with more than 100 species -
although various parts have been separated into Parahebe,
Chionohebe, and controversially into Heliohebe and
Leonohebe. The author shows how New Zealand's climate plays
its part - subtropical in the far north through to temperate in
the far south. It is surrounded by oceans which give a much more
even climate than experienced in the UK. In the section 'Where Hebes
are Found' Lawrie points out that hebes are found in all environments
throughout their native land, from seaside to mountainside. But
in very few places will there be a great variety of hebes, as most
hebes are local in their distribution. Indeed he states that '.it
is amazing how far one may travel in New Zealand without observing
a single hebe in the wild'.
Lawrie looks at each
habitat in turn describing its characteristic hebes. Thus Hebe
elliptica is found growing on the coasts of the South Island.
The large river valleys within mountain ranges have Hebe odora
and Hebe subalpina. In alpine grasslands the whipcord hebes
grow; while Hebe vernicosa occurs in the forests of the Nelson
area, and the grey-leaved Hebe pinguifolia is an inhabitant
of the dry mountain ranges to the north-east of the South Island.
Next he describes the
features of Hebe: the variation in size, the arrangement
of leaves, the prominent terminal leaf bud, and the presence or
absence of a gap (sinus) at the base of the leaf bud. Some drawings
to illustrate these points would have been useful. The related genera
of Heliohebe, ×Heohebe, Parahebe and Chionohebe
are described. This is followed by sections on the discovery of
hebes, early breeding of hebes, and finally the classification of
Hebe into ten informal groups.
Chapter 2 is entitled
'Hebes Around the World'. Here a number of Hebe Society members
give their assessment of hebe growing in the UK, North America,
Europe and Australia. Tony Hayter looks at hebe growing in the UK,
where hardiness, the Hebe Society and the plethora of new hebe cultivars
are mentioned. Neil Bell and Tom Sauceda look at hebes in North
America. Hebes can only be grown in gardens in California or the
Pacific Northwest, and do particularly well near the coast. Elsewhere
it is either too hot in summer or too cold in winter, or both; there
hebes are being sold as pot plants. Claudio Cervelli describes hebe
production and use in a wide variety of climates in Europe. Melanie
Kinsey says that hebes have been grown in Australia for many years,
especially in Victoria and New South Wales. They are much used for
landscaping and warrant their own section in many nurseries.
Chapter 3 deals with
the cultivation of hebes. You would regard growing hebes in their
native land as easy, but Lawrie points out the traps for the unwary.
Hebes bought as a tight ball, if left to their own devices, become
leggy, so they do need regular pruning and deadheading. Hardiness
is rarely an issue in New Zealand, as its winters are relatively
mild, compared to the UK. They appreciate good drainage and a top-dressing
of mulch, and do well in either sun or semi-shade. Hebes grown in
containers need good drainage, feeding with a slow-release fertiliser,
and a yearly potting on, or root pruning. Those grown in open ground
require much less attention, but watering might be necessary in
dry periods. Any fertiliser should be applied to the surface then
worked into the soil, so that it is available to the plant.
Chapter 4 covers the
propagation of hebes. They grow readily from seed, but as hebes
so easily crosspollinate the result may not match expectations.
Semi-hardwood cuttings are best taken in early autumn, preferably
from the sides of the plant. Lawrie then discusses the rooting of
whipcord hebes and growing hebes as standards.
Chapter 5 deals with
growing hebes in different situations in the garden. He considers
how the habitat that a hebe grows in shapes its character, e.g.,
Hebe odora grows well in wet soils, but has to withstand
high moisture loss due to strong winds, and Hebe pinguifolia
has waxy glaucous leaves to cope with dry conditions. The author
shows which hebes are suitable for hedges, rock gardens, ground
cover, dry places, shady places, coastal areas, and damp conditions.
Chapter 6 is about the
pests and other problems, and how to deal with them. Fortunately
hebes don't have too many problems; the key is to have healthy hebes.
Insect pests include aphids, spittlebugs, leaf-rolling caterpillars
and the Hebe gallery fly - the last one occurs just in New Zealand.
Next come the fungal diseases, downy mildew, fusarium wilt, phytophthora
root rot, and septoria leaf spot - Lawrie outlines the methods of
controlling these. Lastly he lists the physical problems that can
affect hebes; drought, frost damage, poor flowering, wind scorch
and rabbits etc. Drought is more of a problem for plants in containers,
so vigilance is needed. To prevent frost damage mulching and a protective
cloth help. Lastly, poor flowering is a more complex problem with
a number of possible causes.
Chapter 7 is the largest
and deals with Hebe species and associated cultivars. The
species are arranged alphabetically, which makes finding a hebe
very easy. However this arrangement does not group related species,
which makes comparisons more difficult. The description of each
hebe starts with its particular characteristics, and its relationship
to other hebes, and may include notes on the various forms available,
the plant's history, and its habitat. Each entry concludes with
a detailed description and notes on its distribution. One that caught
my eye was Hebe 'Swamp', the temporary (or tag) name for
a species that grows in the Hikurangi Swamp near Whangarei, in the
North Island. It has affinities with Hebe bishopiana and
Hebe stricta, with mauve flowers.
Chapter 8 covers Hebe
hybrids and cultivars not directly assigned to a species, and each
is briefly described. Most of these plants will be known to regular
readers of Hebe News, but a number will not, as the book
includes cultivars from New Zealand and Australia. For instance
Hebe 'Flame' has an intriguing name; it's similar to Hebe
'Carnea'.
Chapter 9 covers the
Hebe relatives: Heliohebe (the paniculate hebes, Heliohebe
hulkeana, H. lavaudiana, H. raoulii and H.
pentasepala, and their hybrids Heliohebe 'Fairfieldii'
and H. 'Hagley Park'), ×Heohebe (crosses between Hebe
and Heliohebe), Parahebe and Chionohebe. The
book concludes with a glossary and index.
This book is a worthwhile
addition to those already published on hebes. The range of topics
covered is wide. The text is clear and comprehensive, the photographs
good and useful. I will be sure to keep it within easy reach.
We thank
Tony Hayter for his permission to reproduce a version of his review
originally published in Hebe News, 2006, Vol. 21, No. 3.
Lawrie's
book was also reviewed in The Plantsman (published by the
RHS), Vol. 3, Part 3, in September 2006.
Available
from Touchwood Books
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An
Illustrated Guide to New Zealand Hebes
By Michael Bayly and
Alison Kellow, published by Te Papa Press, PO Box 467, Wellington,
New Zealand, 2006, 388 pages, 28.5 × 20.5 cm, ISBN-13: 978-0-909010-12-6,
ISBN-10: 0-909010-12-9.
Review by Tony Hayter
(aj.me.hayter@boltblue.com)
The Hebe Society
(UK)
Reproduced with
his permission from
The New Zealand Garden Journal (Journal of the Royal New Zealand
Institute of Horticulture), Vol. 9, No. 2, December 2006, p. 27-29.
The September 2002 issue
of Hebe News carried an article by Mike Bayly describing
current research into the genus Hebe. This research aimed
to deliver a range of scientific papers, an interactive computer-based
key for the identification of species, and an illustrated guide.
The guide covers the
identification, classification and biology of Hebe and the
closely related genus Leonohebe. It describes 88 species
of naturally occurring Hebe and five of Leonohebe
(L. cheesemanii, L. ciliolata, L. cupressoides,
L. tetrasticha and L. tumida), but no horticultural
forms. Each plant is illustrated with between six and 13 colour
photographs; these show the whole plant, branchlet, leaf bud, leaf,
inflorescence, flower and capsule. The authors describe each plant
in detail including: habit, branches, leaf bud, leaves, inflorescences,
bracts, flowers, pedicels, calyx, stamens, ovaries, capsules and
seeds. The distribution and habitat are then given, followed by
notes on its relationship with other hebes. Finally the etymology
(origin of the name) is described.
The book is in three
parts: A - general chapters, B - identification, description and
nomenclature of each plant, and C - appendices, glossary, references
and an index.
In the Introduction the
authors point out that Hebe is New Zealand's largest genus,
and is particularly conspicuous in the subalpine and alpine regions.
Hebes occupy a wide range of habitats, from the coasts to the mountaintops,
and have a wide range of forms, from whipcords with tiny leaves
to large-leaved shrubs. Many of the species are similar in appearance,
and can be variable in form, which has given hebes a reputation
as a difficult group to study. It was thought that hybridisation
between species is common, but the authors point out that this has
been exaggerated, so that with care, and the use of a hand lens,
most plants can be identified.
The last complete survey
of Hebe was in the Flora of New Zealand, Volume 1,
1961. Research since that time has described further species, revealed
possible new taxa, and raised questions about the limits of known
species. The research project was planned to try to resolve these
questions, to undertake a biosystematic revision of the genus, and
to look at the evolution of the species. However in 1993 the paniculate
group (Hebe hulkeana, H. lavaudiana, and H. raoulii)
was given generic status as Heliohebe and is not included
in the book, which is a shortcoming. Eleven species have been described
since publication of the Flora, eight species are reinstated
(they were not regarded as such in the Flora), and five hebes
previously classified as species have been discarded.
The second chapter covers
the classification and evolution of Hebe and Leonohebe.
Previously Hebe had been placed in Scrophulariaceae, the
antirrhinum family; but recently the Angiosperm Phylogeny Group
regard it as a member of the Plantaginaceae, the plantain family.
The history of the discovery, description and classification of
Hebe species is given. From 1984 various authors have classified
Hebe based on evolution, at first using the form of each
species and latterly DNA derived data. This supports the idea that
Hebe is derived from Veronica; relationships within
Parahebe and Chionohebe are complex, with most hebes
descending from a common ancestor, although Hebe macrantha
is less closely related. The supposedly close relationship of Hebe
odora and the whipcord hebes is not supported, and the whipcords
fall into several groupings. The classification and naming of species
included in Veronica and Hebe is in a state of flux,
so further research is needed to resolve these problems. The classification
of species within Hebe is based on the Flora, although
a number of changes have been made based on recent but incomplete
research.
The third chapter describes
distribution, habitats and biogeographic history of Hebe,
which occurs throughout New Zealand and its outlying islands. It
is found in most habitats (coastal, near-coast forests, lowland
wetland, riverside, cloud forest, beech forest, lakeshores, subalpine
scrub, grassland and rocky areas in subalpine to alpine regions),
although it is thinly distributed in forests. The number of species
in each area varies widely throughout New Zealand, with the maximum
number of species (25) in mountains at the borders of Nelson, Marlborough
and Canterbury. Here there is a wide range of habitats. Research
shows that Hebe arrived in New Zealand 1.5-5.5 million years
ago, probably in an alpine region; it formed new species in this
region and this was followed by a spread to lowland areas. Hebes
are able to colonise over long distances, and one species (Hebe
elliptica) extends to the Falkland Islands. The limited changes
in DNA confirm the recent origin of Hebe, but more research
is needed to pin down exact relationships within Hebe.
Phil Garnock-Jones has
contributed the fourth chapter, which examines the structure of
Hebe species. Hebes form an extensive system of fibrous roots,
which might explain why they rapidly exhaust the compost in pots.
Many hebes have a bushy habit, due to branching of the stems. These
often have noticeable nodes, i.e., where leaves have been attached.
Leaves have a decussate configuration; where opposite pairs of leaves
are at right angles to their neighbours. A large leaf bud is a common
feature. The leaf sinus, the gap between the bases of the terminal
pair of leaves, can be useful in identification, although it can
be present or absent within one species, e.g., Hebe pinguifolia.
Flowers are usually found as a simple lateral raceme. Other features
he discusses are: hairs, calices, corollas, androecium, pollen,
gynoecium, seeds, seedlings, juvenile forms, and flower development.
Ken Markham has written
the fifth chapter on flavonoids (leaf pigments) in Hebe.
Over 80 flavonoids have been found in Hebe, and each species
has its own (occasionally well-defined) flavonoid profile, giving
it the characteristics of a fingerprint. The profile varies within
each species, but this is much less than that displayed between
species. This analytical method has been used to explore the relationships
between species, and can be used to define hybrids and their parentage.
Chromosomes are the topic
covered by the authors in the sixth chapter, where there is a comprehensive
compendium of chromosome numbers for Hebe. The variation
of these throughout the genus is examined, and work to unravel the
ancestry of hebes is mentioned.
In the seventh chapter
Phil Garnock-Jones considers the reproductive biology of Hebe.
Some aspects have been studied, e.g., maintenance of gynodioecy
(some flowers having male and female reproductive organs, while
others have just female organs), breeding systems for Hebe stricta,
H. subalpina and H. strictissima, and seed shape.
However we have little knowledge of the breeding systems of most
species, their pollinators and development of flowers. Hebe flowers
are structurally similar, although there is a great diversity in
size and detail, but all lack the nectar guides of Parahebe.
The dominant flower colour is white, although some species have
strong colours, e.g., magenta in Hebe speciosa. Most hebes
flower in spring or early summer, with individual flowers lasting
from 2-5 weeks in Hebe strictissima and 2-3 days in H.
pinguifolia. Pollinators are a wide range of insects, although
H. speciosa is visited by birds.
In the eighth chapter
Peter de Lange describes the conservation status of Hebe.
Peter and co-workers have developed a system to classify the conservation
status of New Zealand native plants; this distinguishes between
plants that are under threat from human activities, and those that
are local or uncommon. Hebe is the largest genus in New Zealand,
but few are greatly at risk. 'Acutely Threatened' is the highest
risk category and this contains nine species of Hebe and
one of Leonohebe. Plants in this category are considered
management priorities. This category is further divided into three,
with the highest risk being 'Nationally Critical', in which are
included Hebe breviracemosa and H. societatis. The
former is an island endemic and the latter has apparently very local
distribution in penalpine (between alpine and subalpine) grassland.
Peter then outlines the risks facing hebes, many of which are of
very limited distribution.
The final chapter in
Part A is on cultivation. There is a summary of cultivation requirements,
a list of books on hebes, a mention of the Hebe Society and a photograph
of hebes for sale at a New Zealand garden centre.
Part B, the largest section
of the book, starts with a chapter on Material and Methods. Plants
were studied in the field, and as herbarium specimens and cultivated
plants (of known origin). The authors have arranged the species
into groups similar to those in the Flora, although with
significant differences. Within each group similar species are placed
together. Next there is a list of the characteristics. These are
used to describe each species and are: habit and form, branches,
leaves, juvenile leaves, inflorescences, flowers, pedicels, corolla,
stamens, nectarial disc, ovary and style, capsules and seeds.
Taxonomic Treatment gives
a synopsis of the eleven groups (nine for Hebe, two for Leonohebe)
used for identification. Each group is colour coded, and the distinguishing
features listed. In describing these groups I have given some of
the more well known examples in each.
The first group described
are the 'flagriformes' (whipcords). There is a key to the hebes
in this group, and then each plant is portrayed with a page of text
and a page of illustrations. There are nine species including Hebe
armstrongii, H. hectorii and H. ochracea.
The second group is the
'Connatae' (pairs of leaves are connate, joined at base). This group
has seven species including Hebe epacridea and H. haastii.
The third group is the
'Subcarnosae' (somewhat fleshy), which has dull, grey-green, waxy,
often fleshy leaves and usually no sinus. This group has seven species
including Hebe buchananii, H. gibbsii and H. pimeleoides.
The fourth group is the
'Occlusae' (closed, i.e., no sinus), which has glossy or dull, but
not usually glaucous, leaves (except in Hebe albicans, H.
glaucophylla and H. topiaria). There are 31 species,
and these include Hebe albicans, H. macrocarpa and
H. stricta. Here Hebe recurva has been included with
H. albicans, as recent research has shown that the latter
is very variable and no clear grounds could be found to separate
them.
The fifth group is the
'Buxifoliatae' (box-leaved, a former name for Hebe odora).
The leaf sinus is shield shaped, each flower is directly attached,
i.e., no flower stalk). There are four species, and these include
Hebe odora and H. pauciramosa.
The sixth group is the
'Small-leaved Apertae' (conspicuous leaf sinus). The sinus is narrow;
the leaves are less than 4 cm long. There are 20 species and these
include Hebe diosmifolia, H. elliptica and H. venustula.
The seventh group is
the 'Large-leaved Apertae' (conspicuous leaf sinus). The sinus is
narrow; the leaves are greater than 4 cm long. There are eight species
and these include Hebe salicifolia and H. speciosa.
The eighth group is the
'Grandiflorae' (large flowers). The leaves have noticeable teeth.
There is one species, Hebe macrantha.
The ninth group is the
'Pauciflorae' (few flowers). This is a low-growing subshrub with
leaves narrowing to a conspicuous leaf stalk (petiole). There is
one species, Hebe pauciflora.
The tenth group is Leonohebe
section Leonohebe (semi-whipcords). The plants are low-growing
subshrubs, with leaves overlapping the stems. There are four species
and these include Leonohebe cheesemanii and L. tetrasticha.
These were formerly included in Hebe.
A chapter on nomenclature
follows. It considers the naming at all levels, from the genera
Hebe and Leonohebe, through species to possible wild
hybrids to horticultural forms. Finally there is a list of common
and Maori names.
Part C, Indices, has
an appendix which lists informal hebe names used by Audrey Eagle
in her books, and by A. P. Druce in two checklists. The second and
third appendices describe the variation in some characteristics
of Hebe hectorii and H. lycopodioides. The fourth
appendix illustrates the considerable variation in the size and
shape of the leaf outlines of 40 Hebe species. The fifth
appendix lists the sources of the plant specimens used in the photographs
of hebes and leonohebes. The book ends with a list of references,
a glossary and an index.
This is an excellent
book. The authors have succeeded in presenting a huge quantity of
data which shows the current understanding of Hebe and Leonohebe.
The language used is of necessity technical, but the glossary helps
the attempts of an amateur botanist like me to understand it. The
quality of the text, layout and photographs throughout is very high.
A
version of this review is also published in Hebe News,
2006, Vol. 21, No. 4.
Available from Touchwood
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