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John Weathers.

The bulb book; or, Bulbous and tuberous plants for the open air, stove, and greenhouse, containing particulars as to descriptions, culture, propagation, etc., of plants from all parts of the world having bulbs, corms, tubers, or rhizomes (orchids excluded) online

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Online LibraryJohn WeathersThe bulb book; or, Bulbous and tuberous plants for the open air, stove, and greenhouse, containing particulars as to descriptions, culture, propagation, etc., of plants from all parts of the world having bulbs, corms, tubers, or rhizomes (orchids excluded) → online text (page 1 of 54)
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THE BULB BOOK



THE BULB BOOK



OB



BULBOUS AND TUBEROUS PLANTS

FOR THE OPEN AIR, STOVE, AND

GREENHOUSE



CONTAINING PARTICULARS AS TO DESCRIPTIONS

CULTURE, PROPAGATION, ETC., OF PLANTS

FROM ALL PARTS OF THE WORLD HAVING

BULBS, CORMS, TUBERS, OR RHIZOMES

(ORCHIDS EXCLUDED)



BY JOHN WEATHERS

IUTHOR OF "A PRACTICAL GUIDE TO GARDEN PLANTS," "FRENCH MARKET GARDENING,

"BEAUTIFUL BULBOUS PLANTS," "BEAUTIFUL ROSES," "BEAUTIFUL TREES AND

SHRUBS," "BEAUTIFUL GARDEN FLOWERS," "SCHOOL, COTTAGE, AND

ALLOTMENT GARDENING," ETC.



ILLUSTRATED BY THE AUTHOR



LONDON
JOHN MURRAY, ALBEMARLE STREET, W.

1911



THIS VOLUME ON

BULBOUS AND TUBEROUS PLANTS

FROM ALL PARTS OF THE GLOBE

IS DEDICATED

TO

WILLIAM WATSON

CUBATOK OF THE ROYAL GARDENS, KEW

IN RECOGNITION OF HIS ACHIEVEMENTS AS A CULTIVATOR

AND AUTHOR, AND OF HIS EFFORTS TO PROMOTE THE

WELFARE OF PROFESSIONAL HORTICULTURISTS



2098127



CONTENTS

PAOI

FOREWORDS ........ xi

INTRODUCTION . . . . . . . xiii

BULBS, CORMS, TUBERS, RHIZOMES . . . . 1

FUNCTIONS OF BULBS, CORMS, TUBERS, AND RHIZOMES . . 6

CONTRACTILE ROOTS . . . . . . . 8

CULTIVATION IN THE OPEN Ant . . . . .9

DEPTH OF PLANTING BULBS . . . . . . 11

CULTIVATION UNDER GLASS . . . . - . 12

LIFTING AND STORING BULBS . . . . . . 17

PROPAGATION OF BULBOUS AND TUBEROUS PLANTS . ' . . 19

FORCING AND RETARDING BULBOUS PLANTS . . . . 24

BULBOUS AND TUBEROUS PLANTS FOR Cur FLOWERS. . 26

BULBOUS PLANTS FOR COLD GREENHOUSES AND WINDOW-BOXES . 27

NATURALISING BULBOUS PLANTS IN GRASSLAND AND SHRUBBERIES 29

HARDY AND HALF-HARDY BULBOUS AND TUBEROUS PLANTS . 31

TENDER BULBOUS AND TUBEROUS PLANTS .... 33

FREAKS OF BULBOUS AND TUBEROUS PLANTS .... 35

CLASSIFICATION OF BULBOUS AND TUBEROUS PLANTS. . . 42

GENERA AND SPECIES DESCRIBED IN ALPHABETICAL ORDER . 55

PUBLICATIONS QUOTED AND CONSULTED . . . . 459

GLOSSARY . . . . . . . . . 461

INDEX . V 465



ix



FOREWORDS



There was a time when bulbous plants of all kinds received the
attention of a considerable section of horticulturists. Dean Herbert
was the high priest of the cult, among the most notable of his disciples
being Wilson Saunders, Joad, Michael Foster, Peter Barr, Sir Charles
Strickland, and Max Leichtlin. They collected and cultivated bulbous
plants in the same spirit as predominates among the leading fanciers
of orchids to-day. But with this difference, there wasn't any gambling
in bulbs. There are, of course, certain kinds of bulbs ivhich rank
among the most popular garden plants; but there are scarcely any
collectors of species outside botanical gardens. Bulbous plants of the
Lily, Iris, and Amaryllis families are both numerous and varied.
Many of them are reputedly difficult to cultivate, yet not more so than
orchids used to be. The worst in this respect are the species which
grow naturally in intense sunshine and have a definite period of dry
rest. Such are many of the Crinums, Buphanes, and the JCiphiod
Irises. Years ago, bulb fanciers would meet and discuss the merits
and requirements of their favourites in the most enlightening and
stimulating manner. But how many of the present-day cultivators
show any inclination to do this ? The plants are out of favour, pre-
sumably because they are not easy to manage, an objection that is
generally dissipated by a better knowledge of the essential requirements.
Gardening that is worthy of the name has higher aims than the
cultivation of the vulgar crowd of plants which anybody can 'manage.
The development of orchids as garden plants may be taken as a procf
of what can be accomplished by persevering experiment.

Such genera as Lilium, Gladiolus, Tulipa, Narcissus, Hyacinthus
Crocus, Iris, Galanthus, Hippeastrum, and Nerine have been to a large
extent conquered by the arts of cultivation and breeding; and there



FOREWORDS

are many more which by the application of the same arts would
yield equally successful results. For example, there is an almost
unworked mine of wealth in Grinum, Watsonia, Cyrtanthus,
Hcemanthus, Hymenocallis, Phcedranassa, Zephyranthes, Ornitho-
galum, and Oxalis, genera that are particularly rich in species of
horticultural merit. They and many others are practically unknown
only because they have never had their opportunity. It is only recently
that Freesia, Lachenalia, and Nerine have caught the popular eye;
and the oldest of us can remember the advent of Narcissus as the
glory of the British garden in spring.

Mr Weathers' book is, in my opinion, a praiseworthy attempt to
open up the bulb world to the horticultural explorer. During his
many years' service at Kew, Mr Weathers had exceptional opportunities
to acquire a knowledge of the contents of the large collection there,
and the notes and drawings then and afterwards made he has now
turned to useful account. 1 take the liberty to recommend his book to
all cultivators who take an intelligent interest in plants that are
attractive, either in floral characters, habit, or peculiarities of form
qualities which are prominent in the majority of the species which he
has described and figured.

W. WATSON.



sii



INTRODUCTION

THE cultivation of all kinds of plants having bulbs, conns, tubers,
or rhizomes is now so extended that a volume devoted entirely to
this important phase of Horticulture may be looked upon almost
as a necessity. Coming as these plants do from all parts of the
world, it requires no little skill on the part of the gardener
professional as well as amateur to succeed in their cultivation.
The inclusion of tuberous and rhizomatous plants in this volume
makes it more comprehensive than if it were confined to bulbous
plants proper, all of which belong to one of the two great groups
of flowering plants known as Monocotyledons. As almost any
plant with a swollen root-stock or thickish creeping roots is called
" bulbous " in popular parlance, plants with such peculiarities have
been considered in the present work. In this way about fifty
different natural orders of flowering plants alone have been
included; and these fifty orders include over four hundred
different genera, and some three thousand different species and
varieties. It will thus be seen that even in this age of specialities,
the bulbous and tuberous-rooted plants form quite a respectable, if
not indeed an extensive group by themselves.

Considering these plants from a geographical point of view,
it will be noticed by a reference to their native countries that they
not only come from every part of the globe from the tropical,
subtropical, and temperate regions but also from the highest
altitudes and the lowest plains. In such a range of bulbous vegeta-
tion, many temperatures, climatic differences, and soil variations
naturally exist. The gardener therefore has to make himself more
or less acquainted with the peculiar requirements of any particular
plant, if he wishes to achieve anything like success. He must
recognise that a plant from the tropics is not necessarily a subject
to be grown in a hothouse or a greenhouse, unless it comes from
the plains, or is found only at low elevations. Many mistakes

xiii



INTRODUCTION

have been made in the past because the various altitudes at which
plants grow naturally were either unknown or were ignored. Thus
it happened that plants from the tops of the Andes of Ecuador,
Colombia, or Peru, although within the Tropic of Capricorn and
beneath an equatorial sun, were found to die with warm house
treatment, while they nourished under a temperate or almost hardy
regime. The proper temperature, etc., for a plant in cultivation
may be therefore more easily gauged if the gardener possesses
accurate information as to the condition in which it grows in a
state of nature. Owing to these variations of altitude and
temperature, it has become necessary to divide bulbous plants
into four main groups, namely: hardy, half-hardy, greenhouse, and
hothouse or stove. In the following pages under each genus such
particulars as to the native habitat of each species are given as
will enable the gardener to arrive at a decision as to the
temperature most likely to suit his plants.

While temperature of course plays an important part in plant
cultivation, the questions of soils, moisture, drought, etc., have
also to be considered. Here again a knowledge of the local natural
surroundings will give one a fairly good idea as to what compost
should be used, and whether much or little water is to be given. A
plant that grows naturally in a peaty or marshy soil would be likely
to flourish in a similar compost, but would in all probability die
in a very short time if planted in heavy clay or coarse sand,
although it might do fairly well in a moist loamy soil. On the
other hand, plants from desert regions where sandy wastes abound
will probably require a hot, dryish atmosphere, although they may
enjoy moisture at the root during the period of active growth.
Others again from the lower elevations of tropical regions can
scarcely be given too much heat and moisture in conjunction with
a rich and unctuous soil. To enable the gardener to judge which
set of conditions is most likely to suit any particular group of
bulbous or tuberous plants, this volume has been specially written,
and the author hopes that it may prove itself worthy of frequent
reference on the part of the intelligent cultivators in all parts of
the British Islands.

A glance at the page of Contents will give the reader a kind of
bird's-eye view of the scope of the work. In the descriptive portion
the various genera and species have been dealt with in alphabetical
order, as it is probably the most generally convenient. Those plant-
lovers, however, of a studious or analytical turn of mind, will find

xiv



INTRODUCTION

the natural relationships of the different genera by turning to the
Chapter on Classification.

The derivation of the names of the genera and the natural orders
or families to which they belong have been given, in the hope that
the information will be not only interesting in itself, but also of an
instructive character.

It is also hoped that the numerous drawings (many of which
are reproduced from sketches made twenty-three and twenty-four
years ago) will serve a similar purpose, and help to make clear any
little obscurities in the text. With a view to encouraging still
further research, references to coloured plates and good figures in
standard botanical and horticultural works have also been added
after the descriptions of many species and varieties.

JOHN WEATHEKS.



THE BULB BOOK



BULBS, CORMS, TUBERS, RHIZOMES

OUTSIDE the ranks of botanists and skilled gardeners, much
uncertainty and no little confusion prevail as to what constitutes
a bulb, a corm, a tuber, or a rhizome. It may be well therefore to
say a few words about each, with a view to making things plainer in
regard to these matters.

BULBS. A bulb is a special kind of bud bearing a number of
thickened fleshy or scaly learns closely packed together and seated
upon a flattened compressed or disc-like woody stem, from the under-
surface and edges of which roots are produced during growth.
Examples of true bulbs that will fit this description may be seen in the
Onion, Tulip, Hyacinth, Daffodil, Snowdrop, Squill, the Snowflakes,
and many others. In most cases the fleshy leaves are rolled round
each other ; the bulbs are then said to be tunicated. In the case of
the Liliums, however, in which the thickened leaves are overlapping
each other in a spiral fashion round the main axis, the bulbs are said
to be scaly or imbricated. The drawings will give a good idea as to
the difference between " tunicated " and " imbricated " or " scaly
bulbs." Figs. 1 to 3 represent the former; Fig. 4 represents the
latter.

CORMS. These are often described as " solid " bulbs, owing to the
fact that in many cases they bear a superficial resemblance to bulbs
proper. In many cases, however (e.g., the tuberous Begonia and the
Cyclamen), the term "corm" is very loosely and erroneously used
when speaking of the tubers of these plants. The one obvious
difference between a true bulb and a true corm is, that the latter is
quite solid, and has neither tunicated, imbricated, nor scaly leaves
seated on a compressed disc-like stem, a section of which is shown
in Fig. 1. The corm is a rounded or flattish stem on which traces of
the leaf -stalks or bases may be seen. Another great difference

1 A



THE BULB BOOK

between the bulb and the corm consists in different methods of
growth. Many bulbs will grow for years and produce numerous

offsets. Conns, however, dwindle
away and shrivel up each year
after having yielded up their
store of nourishment for the pro-
duction of new flowers and
leaves; and their place is taken




FIG. 1. Galtonia ca.ndica.ns, bulb section
of same. (J.)




FIG. 8. Nothoscordum, bulb and seclion



by quite new conns, which have been developed by the action of
the leaves in the daylight. Thus, the conns of Crocus (Fig. 5)
and Gladiolus (Fig 6), etc., that are put into the soil are not the
same as those that are taken up after growth has ceased. They
are quite new vegetative creations.

Although conns and bulbs differ from each other in structure and
2



BULBS, CORMS, TUBERS, RHIZOMES



vegetation, it is remarkable that both of them are confined to one

particular class of flowering plants that known botanically as

Monocotyledons. These are plants

that are easily recognised by

having (1) leaves with parallel or

curvilinear veins; (2) the parts

of the flowers (i.e., the petals,





FIG. 5. Crocus, showing new corm on top
of old one.



FIG. 6. Gladiolus, two new conns over old
one, with " spawn ' at base.



stamens, and carpels) arranged in three's or six's ; and (3) when raised
from seed, by having only one seed-leaf.

If these characteristics are borne in mind there will be no
difficulty in distinguishing a true bulb or a true corm.

TUBERS. A tuber may be described as a short and more or less
thickened or swollen shoot or stem furnished with " eyes " or buds.




FIG. 7,Oxu.lis crenata.



FIG. 8. Tropceolum
EXAMPLES OF TUBERS.



(*)



Good examples are seen in the Potato and the Jerusalem Artichoke ;
others are the tuberous Begonia, the Cyclamen, the Anemone, Kanun-
culus, Aconite, the Arum Lily, Caladium, some Tropseolums, etc. The
Dahlia and herbaceous Paeony are examples in which the true roots
are swollen and of a tuberous nature, but they contain no vegetative
buds. These are borne at the base of the old flower-stems, portions
of which should be always retained when the plants are lifted and
stored away. Examples of tubers are shown in Figs. 7, 8, and 9.

3



THE BULB BOOK

It should be noted that while all true bulbs and corms are
confined to the Monocotyledons, tuberous plants have a much wider
range. They are to be found not only amongst Monocotyledons, but
also amongst the other great group of flowering plants known as
Dicotyledons. These are generally recognised
by having (1) net-veined leaves ; (2) parts of
the flower (i.e., the sepals, petals, stamens,
carpels) in four's or five's, -or multiples of
them; (3) and when raised from seed, by
having two seed-leaves. An apparent con-





FIG. 9. Richardia cetMopica.



Fio. 10. Seedling Cyclamen, showing aberration
from ordinary dicotyledonous type.



tradiction to this arrangement is seen in the seedlings of Cyclamen,
as shown in the sketch (Fig. 10). When the seeds first germinate,
only one seed-leaf is apparent ; later, a second one much smaller than
the first appears, and with advance in age one leaf succeeds another
rapidly until the top of the tuber is furnished with a good supply.

RHIZOMES. A rhizome is a shoot or stem that grows more or
less horizontally, and usually beneath the surface of the soil. Many
plants have rhizomes, some thickened and somewhat tuberous,
others slender. Good examples of plants with thick rhizomes are
the German and Florentine Irises or "Flags" (Fig. 11), and Solomon's
Seal (Fig. 12); while the Lily of the Valley (see Fig. 99, p. 149)
may be taken as an example of a plant with slender rhizomes.

In the Tritonia or Montbretia (Fig. 13) we have an example of
plant in which both corms and rhizomes are developed. It will be
seen from the sketch that the corms are not actually placed upon
each other as in the Crocus and Gladiolus, but are separated by a
kind of runner-like rhizome, some joints of which swell into a corm
if sufficient nourishment has been elaborated by the leaves.

4



BULBS, CORMS, TUBERS, RHIZOMES



While it is easy in many cases to distinguish the true bulbs,
corms, tubers, and rhizomes, there are instances in which the swollen

portion of the plant seeins
to be intermediate between
one or the other. The root-
stock of the Tigridias or Tiger
Flowers, for example, is called
a "corm," but a reference to





Fio. 11. Rhizomes of German Iris. (J.) FIG. 12. Rhizomes of Solomon's Seal. (J.)

Fig. 14 shows that it is more like an ordinary tunicated bulb.

The root-stocks of Erythro-
nium (Fig. 15), Colchicum (Fig.
16), and Bulbocodium (Figs. 17
and 18) are also known as corms.
It will be seen, however, that





Fio. 13. Corms and rhizomes of Tritonia
(Montbretia) crocoscemiflora. (.)



Fio. 14. Tigridia, bulb and section
of same. (J.)



the vegetation of these plants is not like that of the Crocus or

5



THE BULB BOOK

G-ladiolus. The new corms, instead of developing on top of the old
ones, are produced at a lower depth from a downward growth.






FIG. 15. Corm or bulb of Erythronium, showing FIG. 16. Conn of Colchicum, showing new

new lower growth to right. growth to left.

In this way there is no likelihood of the new corms coming too
near the surface to be injured by frost, etc.





FIGS. 17, 18. -Corm and section of Bulbocodium, showing new
lower growths at side.

This volume is devoted to those plants which have either bulbs,
corms, tubers or tuberous roots, and rhizomes, and therefore embraces
many families of flowering plants (both Monocotyledons and
Dicotyledons) from all parts of the world. Orchids a large and
important family requiring a volume to themselves are excluded.



FUNCTIONS OF BULBS, CORMS, TUBERS,
AND RHIZOMES

Apart from the plants described in this volume being characterised
by having either bulbs, corms, tubers, or rhizomes, they all agree in
one important respect they are all herbaceous plants and they are
all perennial. That is to say, their aerial parts (flower-stems and



FUNCTIONS OF BULBS, CORMS, ETC.

leaves) are soft and herb-like in texture, and there is nothing woody
about them as seen in trees and shrubs, and their underground
organs may live for several years. The possible exceptions are
Beschorneria and Testudinaria, which have swollen woody bases.
It will prevent misunderstanding to state that perennial herbaceous
plants 1 may be divided into various groups. Thus they may be
either (1) hardy, (2) half-hardy, or (3) tender each group requiring
different culture, treatment, and temperature. Again, herbaceous
perennials may be either (1) deciduous, in which the floral stems
and leaves die down every year, and the root-stock has a period of
rest (as in Tulips, Daffodils, Hyacinths, Begonias, Pseonies, Solomon's
Seal, Arum Lilies, etc., etc.) ; or they may be (2) evergreen, in which
the plants are always in a state of growth, and have foliage at all
periods of the year (as with Pancratiums, many Crinums, some
Irises, etc.).

It may be well to bear these distinctions in mind, as there is a
popular and consequently erroneous impression that all herbaceous
plants are hardy and die down to the ground each year.

We may now consider why certain plants are provided with
bulbs, corms, tubers, or rhizomes. We have already seen that the
normal stem has been reduced in the case of the bulb to a very
small compass a mere disc-like mass with the thick fleshy leaves
densely arranged upon it. If a bulb of a Tulip, Hyacinth, or Daffodil
is cut through vertically and compared with a ripened bud of a
Horse-chestnut, Lilac, or Ash, it will be seen that they are all very
similar in structure. In the centre will be found the miniature
flower - stem with its incipient blossoms packed away into the
smallest possible compass, and carefully protected with the envelop-
ing scales really leaves specially modified for this particular
purpose. In the case of bulbs, however, which are detached and
independent bodies (unlike the buds of the Horse-chestnut, etc.), the
scale leaves are not only protectors ; they are also storehouses in
which food and nourishment have been stored away by the green
aerial leaves before these withered and died. The corm or solid
"bulb," and also the tuber and rhizome utilise the stem, and not
modified leaves, in which to store up their nourishment in the same
way for the development of future growth. Consequently, season
after season this work is going on, and as the older storehouses

1 " Annuals " and {i Biennials " of all kinds are necessarily herbaceous in
character, but are not considered in this volume, as they have neither bulbs,
corms, tubers, nor rhizomes.



THE BULB BOOK



(either as bulbs, conns, tubers, or rhizomes) decay and die, they are
replaced by new ones. If it were not so, especially in our climate,
there would be great danger in many cases of the plants dying out
altogether especially as many of them are difficult or impossible to
raise from seeds. When there seems to be any risk of a plant being
unable to reproduce itself readily by means of seeds, Nature has
endowed it with the power of multiplying itself in other ways which
are considered under the Chapter on " Propagation."

The point to bear in mind, however, at present is that the new
bulbs, corms, tubers, or rhizomes underground can only be produced
by the healthy assimilative action of the leaves, and the absorptive
powers of the roots.

CONTEACTILE EOOTS

In connection with the annual reproduction of new corms in
such plants as Crocus, Gladiolus, etc., it is interesting to notice
a very extraordinary action of the roots. During the period of
growth if a corm of a Gladiolus or Tritonia (Fig. 19) be taken out of
the ground carefully it will be noticed that there are two kinds of

roots present (1) the fibrous
feeding or absorbing roots, and
(2) thicker ringed roots. The
latter play a very important
part in keeping the new corms
at a proper distance beneath the
surface of the soil. It is obvious
that by the superposition of the
new corms on top of the old ones
year after year, there would be
a danger eventually of them
coming through the surface of
the ground. They would thus be
exposed to the dangers of frost,
etc. It is well known, however,
that neither corms nor bulbs, no
matter how many years they
have been in the soil, ever come through the ground. On the
contrary, they seem to bury themselves deeper and deeper, thus
keeping away from the frost, and in surroundings several degrees
warmer than the soil immediately at the surface.

8




PIG. 19. Tritonia Pottsi, showing new corms
and contractile roots.



CULTIVATION IN THE OPEN AIR

Corms and bulbs are kept down in the soil in this way by means
of special roots called " contractile." These are the thickish ringed
roots referred to and shown in the sketches (see Figs. 3, 6, 14, 19).
It appears that when the new corms or bulbs have developed fairly
well, these contractile roots have already pushed their way deeper
into the soil, lower than the older corms. In due course they begin
to contract, and in this way they exert sufficient force to pull down
the new corms to a lower level, perhaps even lower than the parents
were the previous season. The marvellous power possessed by these
contractile roots is one of the most mysterious functions of bulbous
plants, and it is only another instance showing how carefully and
beautifully everything was thought of " at the beginning."



CULTIVATION IN THE OPEN AIK

SOILS AND COMPOSTS

If this volume were confined to the consideration of hardy plants
alone, it would be a comparatively simple matter dealing with the
soil. But as we are dealing not only with hardy plants that may be
always grown in the open air, but also with those that must be
sheltered in a greenhouse and hothouse and are often grown in pots,
it becomes necessary to take a wider view of the subject, treating
the outdoor cultivation and the indoor separately.

Generally speaking, most of the hardy bulbous, tuberous, and
rhizomatous plants (of which a list is given at p. 32) will flourish



Online LibraryJohn WeathersThe bulb book; or, Bulbous and tuberous plants for the open air, stove, and greenhouse, containing particulars as to descriptions, culture, propagation, etc., of plants from all parts of the world having bulbs, corms, tubers, or rhizomes (orchids excluded) → online text (page 1 of 54)