265
J . Linn. SOC.(Bot.), 59,379, p . 265
W i t h 2 plates and 5 texttlfigures
Printed in Great Britain
Febrmry, 1966
Development of stomata and foliar structure of some
Magnoliaceae
BY DIVYA DARSHAN PANT, F.L.S. AND KUSUM LATA GUPTA
Department of Botany, The University, Allahabad, India
(Accepted for publication August, 1965)
INTRODUCTION
The systems of classification of Angiosperms proposed by Bessey (1894, 1915), Hallier
(1905, 1912), Hutchinson (1959), Tippo (1942) and others as well as the theories of
Angiosperm evolution put forward by Arber & Parkin (1907)believe that the Magnoliaceae
(sensu Hutchinson) or the Magnoliales-Ranales complex represents the surviving starting
point in the angiospermous line of evolution. Different plants of this complex retain in
their organization, up t o the present day, many a n archaic feature like vesselless wood,
scalariform perforation plates in trachae, unilacunar two trace nodes, dichotomous
venation in leaves, spiral or spirocyclic flowers with indefinite number of free parts and
conduplicate carpels. Their morphology has naturally attracted the attention of many
botanists. Recent work on various aspects of these plants seems t o have strengthened
the ideas about the primitiveness of this complex, thus keeping our interest in their
morphology undiminished. A line of enquiry into the structure of these plants relates
to their epidermal structure. The epidermis of the mature leaves of a number of
magnoliaceous plants was described by Rao (1939),Bailey & Nast (1945,1948),Bondeson
(1952), Jalan (1962) and Paliwal & Bhandari (1962). Rao also drew inferences on the
stomatal development of these plants on the basis of the form and arrangement of cells
around the mature guard cells. An investigation of the division of stomatal initials in
plants of the family was first made by Bondeson (1952)who studied Drimys, Trochodendron
and Tetracentron. Later, stomatal development of Schisandra grandiJlora was worked
out by Jalan (1962)and that of Magnolia stellah, M . grandi$ora and Michelia champam
by Paliwal & Bhandari (1962).The last mentioned authors observed that the development
of stomata in leaves of their plants was different from that of stomata in perianth lobes.
Their observations did not confirm the earlier conclusions of Rao about the transverse
or longitudinal divisions in the subsidiary cells of the Magnoliales. The work of these
authors is a t variance with the constancy of stomatal development noticed by Jalan
throughout the plant of Schisandra. The contradictions involved in the various papers
on stomatal ontogeny led us to look for the development of stomata in some of these
plants and we find that our preparations neither fully confirm the conclusions of Rao
(1939) nor the previous observations of Paliwal t Bhandari (1962).Incidentally, we have
noticed a number of hitherto unrecorded anatomical features in the leaves of our plants
and these too are detailed below.
MATERIAL, METHODS A N D TERMINOLOGY
Material of the plants for the present work was collected, or obtained from (1) the
private garden of Mr J. N. Chaudhari, Allahabad; (2) Lloyd Botanic Gardens, Dajeeling;
(3) Botanical Garden of the Forest Research Institute, Dehra Dun; (4) garden of
266
DIVYADARSHAN
PANT,
F.L.S.
AND
KTJSTJM
~
T
GUPTA
A
Trichandra College, Kathmandu (Nepal); (5) National Botanic Gardens, Lucknow.
Sources of the various species are indicated below by their numbers.
A.
B.
C.
D.
E.
F.
G.
H.
I.
Magnolia grandijlwa Linn. : ( l ) , (3), (4), (5).
M . obovata Thunb.: (2), (4).
M . pterocarp Roxb.: (1).
M . p m i l a Andr.: (l),(4).
x M . soulangiana Soul ( M . denudata Desrouss x M . lilijlura Desrouss)
(3). We are informed that the plant from which Paliwal & Bhandari obtained
their material of ' Magnolia stellata' was wrongly labelled and that it has now been
identified as M . soulangiana.
Michelia cathrtii Hook. f. & Thorns. : (2).
M . champaw Linn. : (3), (5).
M . fuscuta Blume: (3), (4).
M . oblonga Wall.: (3).
Young and mature leaves as well as flower buds were fixed in acetic alcohol (1:3) and
later stored in 70 % alcohol. (The flower buds of Michelia c a t h r t i i and M . oblonga were
not available). Development of stomata was studied in epidermal peels of young leaves,
sheathing stipules and perianth lobes after staining them in acetocarmine. Epidermal
peels of mature leaves, sheathing stipules, and perianth lobes were mounted in acetocarmine as well as in safranine glycerine jelly. Cuticles of mature parts were prepared
by macerating them with concentrated HN03 +KClOs and subsequently after washing
the acid in water with dilute NH4OH. Clearing techniques (using dilute solution of
NaOH and concentrated solution of chloral hydrate) were employed for examining the
sclereids in situ. Microtome sections were cut a t 10-12 microns and stained in safranine
and fast green. The terms used here in the description of stomata and their components
are the same as those used by earlier authors (see Pant, 1 9 6 5 ~ )The
.
terms secondary
mesogene subsidiary cells and secondary mesogene encircling cells are used for cells
which are secondarily formed by divisions of mesogene neighbouring cells.
OBSERVATIONS
Epidermis. The leaves of all investigated plants are invariably hypostomatic but their
sheathing stipules and perianth lobes are amphistomatic. The anticlinal walls of mature
epidermal cells are almost straight, slightly or deeply sinuous in the leaves (Text-fig.
1 A-G, Text-fig. 2A-E; P1. 1, fig. 1) and straight in other organs. The walls of the lower
epidermal cells are conspicuously pitted in Magnolia grandiJEora (Text-fig. 2F), M .
p m i l a and Michelia fusmta.
No hairs were seen in the leaves of Magnolia p m i l a and Michelia obknqa but these
are present in all other species (see Metcalfe & Chalk, 1950). I n M . cathcurtii and M .
fusmta they are generally present over the midrib on the upper face. Hairs are also found
scattered all over the lower side of leaves of M . fuscuta, only on the lower tomentose side
in Magnolia g r a n d i w a and on both surfaces in M . p t e r m r p , M . obovata, M . soulangiana
and Michelia champaw.
Calcium oxalate druses are present in cells of the upper and lower epidermis of leaves
of Magnolia pterocurpa (Text-fig. 2G), Michelia champam and M . cuthcurtii.
Epidermal peels of mature leaves of Michelia fuscata, Magnolia p m i l a and M .
grandijlura (Text-fig. 2E) when stained with Sudan IV, usually show single or multiple
oil globules of varying sizes.
All young epidermal cells on either side of leaves of Magnolia p m i l a (Text-fig.2H,
Text-fig. 3A, B) and generally only the lower epidermal cells in M . grandiJEora (Text-fig.
3C; P1. 1, fig. 4) contain a peculiar rod- or dumb bell-shaped structure. Occasionally
there may be two bodies of this type in a cell or one end of a rod may be forked to become
S‘tomata and foliar
structure of S o m e iJIagnoliaceae
Text-fig. 1. A-G. Lower epidermis of mature leaves. A. Magnolza pterocurpa. B.M . pumzla.
C. iM.grandafiora. D. Af. obovata. E. ‘ M . soulangzana’. F. Mzchelza cathcartaa. G. M . juscata.
Thickened lamellae of guard cells cross hatched, nuclei represented by thew outhnes. D x 225;
others x 300.
267
268
DIVYADARSHAN
PANT,
F.L.S. AND KTJSTJM
LATAGUPTA
Text-fig. 2. A, B. Lower epidermis of mature leaves of Michelia chumpaca and M . oblonga.
Thickened lamellae of guard cells cross hatched. C E . Upper epidermis of mature leaves;
C. Magnolia pterocarp. D. M . pumila. E. M . grandiJlwa (oilglobules dotted). F. A few cells
of the lower epidermis of a mature leaf of M . grandiJlwa m a w e d to show pitted anticlinal
walls. G. A portion of lower epidermis of mature leaf of M . pterocarpa m a w e d to show single
calcium oxalate druses in each cell. H. Lower epidermis of young leaf of M . pumila showing
rod-like bodies. Nuclei shown by outlines. A-E, H x 300. F, G x 450.
Stomata: and foliar structure of some Magnoliaeeue
269
Y shaped. The rods are absent in epidermal cells of very young leaves (till they are about
3-4 om. long) and usually they once again disappear from the epidermis of mature leaves.
A few histochemical tests were tried to determine the chemical nature of these rods.
Iodine for starch, phloroglucinol for lignin, IKI +H2S04 and chlor-zinc iodide for cellulose
and Sudan IV for fats and cutin gave negative results. The rods also failed t o give biuret,
Millon’s, Sakaguchi and ninhydrin tests for proteins. However, they did take a deep
blue stain with mercury bromophenol blue but that may not be accepted as a n indubitable
proof of their proteinaceous character.
Mature stomata. The stomata in leaves of Magnolia g r a n d i w a nearly all show one
subsidiary cell alongside each guard cell (the rubiaceous or paracytic arrangement). Most
leaf stomata of the other plants studied are similar but some are of the ranunculaceous
(anomocytic) type. A rubiaceous stoma may be monocyclic, without encircling cells or
it may be incompletely or completely amphicyclic with a n encircling cell on one side
or one on either side (Text-fig. 3D; P1. 1, fig. 2). I n a few stomata of different plants the
place of each encircling cell is seemingly occupied b y 2 or more shorter or narrower cells
and likewise in some anomocytic stomata even the subsidiaries appear t o be replaced
by 2 or more smaller cells. Such stomata were never seen in Magnolia grandiJlora. On the
contrary, a vast majority of stomata in the sheathing stipules and perianth lobes of all
our plants are ranunculaceous (Text-fig. 3E) but rarely they too may be rubiaceous.
A few stornatal apparatuses with one or two parallel subsidiaries appear exceptional in
being enclosed by an anisocytic ring of 3 encircling cells (Text-fig. 1 G centre) in all the
plants examined.
Abnormal structures observed include (i)arrested stornatal developments with groups
of 2 or more parallel cells representing various stages before the formation of typical
guard cells or a pore between them. Some of these structures in Michelia fuscata even
develop pores between the arrested components of such cell groups (Text-fig. 3F), (ii)
pores bounded by 3 or more ordinary epidermal cells whose walls are thickened on the
side of the pore are found only in Michelia fuscata, (iii) contiguous stomata (Text-fig. 3 6 ) .
Some laterally contiguous twin stomata have their 4 guard cells placed side by side
and there are also a few 3-celled twins found in Michelia fuscata where a central common
guard cell intervenes between 2 pores (Text-fig. 3 H).
The outer walls of the guard cells in Michelia (except M . oblonga) frequently show
thickened lamellae on either side ofthe pore (Text-fig. 1 F, G , Text-fig. 2A). I n all stomata
whose guard cells are thus thickened the dorsal wall becomes obscure and as a result it
appears as if the pore is formed only by the 2 subsidiaries without the intervention of
guard cells. The frequency of such stomata is about 39 yoin Michelia cathcartii but it is
much lower in M . fuscata and M . champca. The form of the lamellae seemingly resembles
that of the cutin or lignin lamellae in typical gymnospermous stomata. However, they
neither give the test of cutin nor of lignin but a t the same time they are as resistant to
maceration as the cuticle.
I n the foliar stomata of all investigated species the guard cells are normally placed
above the subsidiaries (Text-fig. 31-N) but they lie more or less a t the same level in
those stomata of Michelia whose guard cells show thickened lamellae (Text-fig. 3 0) and
also in stomata of its perianth lobes and sheathing stipules.
Cuticle of leaves. Cuticles of leaves of all plants show clearly marked cell impressions.
The surface of the guard cells shows thickened cutin lamellae on both sides of the pore
in all species of Magnolia (Text-fig. 4A-C). The cutin lamellae of the guard cells of
Magnolia pumila (Text-fig. 4C) show a prominent circular ridge around the pore which
is discontinuous opposite the 2 poles and often a t other points. All guard cells of Michelia
show thin ledges of cutin around the pore. The occurrence of thickened lamellae in guard
cells of a few stomata of this genus has already been described.
Development of stomta. The development of stomata in leaves of all our plants is
typically mesogenous. The meristemoids lie scattered on the lower surface of young
19
270
DIVYA
DARSHAN
PANT,F.L.S. AND KUSUMLATAGUFTA
I
L
Text-fig. 3. A, B, D, K-M. Magrwliapmila. C , J. M . grandi&ra, E. M . obovata. I. M . petrocarpa. F-H, N, 0 .Michelkz jwcuta. A. Upper epidermis of young leaf showing rod-like bodies.
B. Part of a T.S.of a young leaf with rod-like bodies in the upper epidermal cells. C. Lower
epidermis of young leaf with rod-like bodies. D. Mature amphicyclic stornatal apparatus with
a circular cutin ridge (black) around the pore which is discontinuous opposite the 2 poles
and a t 2 other points. Nuclei of guard cells are elongated, rounded nuclei of subsidiary
cells are shown by dotted lines. E. Mature (anomocytic)stoma in lower epidermis of sheathing
stipule. F. Arrested stornatal development with a pore between the guard cell initial and a
subsidiary. G. A row of closely placed stomata, 2 of which are laterally contiguous. H. A 3celled twin with 2 pores between 3 guard cells. 1-0. Sectional views of stomata. Thickened
lamellae of guard cells cross-hatched, cell walls dotted, cuticle black. A-C, G x 300. D x 575.
E x 225. F, H x 450.1-0 x 600.
272
DNYA DARSHAN
PANT,
F.L.S. AND KUSUMLATAGUPTA
walls cutting off these segments usually meet or intersect a t both the poles of the meristemoid making i t lenticular. Sometimes the partitions on the 2 sides meet only on 1
side and as a result the meristemoid remains triangular. In any case, the segments adjacent
Text-fig. 5. A-I. Peek of lower epidermis; A-E of young leavesand G-I of sheathing stipules
of Magnolia pterocarpa. A-C. Further stages (after Fig. 4 L) leading to the formation of a
completely amphicyclic stoma in C. D. A developing stoma showing divisions in the neighbowing cells. E . A developing stoma showing a lenticular meristemoid and 3 mesogene
neighbouring cells-the 2 smaller cells are parallel to the meristamoid and the larger one is at
a slight angle to the others (see aho Plate 1, fig. 3). F. MicheZia fuscata.A triangular meristemoid with e metaphase plate formed a t right angles t~ the first wall. G . A stoma with 2
subsidiary cells 1 of which has partitioned and the other shows 2 nuclei after division. H. A
stoma with 2 undivided subsidiary cells. I. A stoma with some irregular looking neighbouring
wlls already partitioned and 1 of them with a nuclear spindle. J, I(.M . pterocarpa. J. Isolated
brachysclereids from sheathing stipule. K. Intact groups of brachysclereids. A J x 450.
K x75.
t o the guard cells turn into 2 parallel subsidiaries and where present, the remaining 1 or
2 peripheral segments mature into the encircling cells (Text-fig. 4D-M; Text-fig. 5A-C).
The subsidiary cells of Magnolia obovata, M . soulangiana, Michelia champam and AM.
mthcartii often divide by radial, tangential or oblique walls but they do so only rarely
in illagnolia purnila (Text-fig. 4E), M . pterocarp, Michelia fuscata and M . oblonga.
Likewise, the encircling cells of the stomata of all the above plants may also divide and
give rise to a multicelled irregular ring of mesogene cells. These divisions may take place
Stomata and foliar structure of some Magnoliame
273
before, after or simultaneously with the formation of the guard cells. The frequency
of divisions of subsidiary and encircling cells varies in different plants (see Table 1).
A few stomata of all our plants show a ring of 3 unequal encircling cells around the
subsidiaries. Their form suggests a mesogenous development like that of the encircling
cells in Bryophyllum calycinum (Yarbrough, J. A., 1934) and this is confirmed by the
orientation of metaphase plates of successive divisions-the plates are often a t wide
angles with the partition wall formed during the previous divisions (Text-fig. 5F).Again
successive walls formed by a few stomatal meristemoids are not exactly parallel but a t
small angles suggesting that such stomata are actually transitional between the anisocytic
and paracytic types (Text-fig. 5 E ; P1. 1, fig. 3).
Table 1. Variations in the development of paracytic stomata
I n leaves
Species
Magnolia
grandijera
M . pumila
No. of
encircling
cells
1 or 2
1 or 2 in most
stomata
M . pterocurpa 1 or 2 in most
stomata
M . soulangiana 1 o r 2 i n f e w
stomata
1 in some
M . obovata
stomata
Miehelia
1 or 2 in most
stomata
oblonga
M . fuscata
M . champaca
M . cathcartii
1 or 2 in some
stomata
1 or 2 in few
stomata
1 in some
stomata
In sheathing stipules and perianth lobes
Frequency Divisions
of divisions in parallel
in encircling subsidiary
cells
cells
Not seen
Not seen
No. of
encircling
cells
1 or 2 in some
Common
stomata
Rare
1or 2 in very few
stomata
Rare
1 or 2 in very few
stomata
Common Not seen
Common
Common Not seen
Rare
Rare
Occasional
(in sheathing
stipule only)
Rare
1 or rarely 2 in
some stomata
Common 1 seen rarely
Rare
Occasional
Common
Common
1 or 2 rarely seen
Common Not seen (in
sheathing
stipule only)
Frequency of Divisions
divisions in in parallel
encircling subsidiary
cells
cells
Common
Common
Common
Common
Common
Common
Common
Common
Common
Common
Common
Common
Common
Common
Common
The development of stomata in the sheathing stipules and perianth lobes of Magnolia
grandiJlora is generally like that described for its leaves (Pl.2, fig. 5 ) . The same is true
of a few stomata of the perianth lobes of Magnolia pterocarp, M . pumilu, Michelia
champca and M . fuscata as well as their sheathing stipules and those of Michelia oblonga
but a majority of such stomata in these plants and a few in Magnolia grandi$ora show a
suppression of 2 of the first 4 divisions. This suppression of divisions becomes practically
universal in the stomata of the perianth lobes of Magnolia soulungiana and M . obovata
as well as their sheathing stipules and those of Michelia cathmrtii. Almost all their stomatal
meristemoids which are located in these parts form only 2 mesogene subsidiaries, 1 on
either side of a stoma. Subsequently the subsidiary cells and also, if present, the encircling
cells divide in various planes. Formation of radial and oblique walls during these divisions
makes the stomatal apparatus anomocytic (Text-fig. 51; P1. 2 , figs. 6, 7). Where any
periclinal walls are formed, the stomata become completely or incompletely amphicyclic
(Text-fig. 5 6 ) . Nevertheless, one can always locate a few paracytic stomata with
undivided subsidiaries (Text-fig. 5 H ; P1. 2 , fig. 8). The development of a few stomata is
anisocytic as in the leaves (Pl.2 , fig. 9).
Sclereids. Sclereids occur plentifully in leaves, sheathing stipules and floral parts of
274
DIVYADARSHAN
PANT,
F.L.S. AND KTJSUM
LATAGUPTA
all investigated plants. Two types of sclereids are distinguished (i) thick walled brachysclereids and (ii)thin walled vesiculose sclereids.
The walls of brachysclereids may be very thick or relatively thin and they may be
polygonal or lobed. Isolated brachysclereids occur singly in the hypodermis of leaves
of all plants. Scattered groups or isolated brachysclereids are also found over the midrib
and attached to the vein ends of leaves of all investigated plants. In Michelia cathcartii
they flank the smaller veins also. In Af. fusmta they occur even a t the vein ends in
perianth lobes. They are found isolated (Text-fig. 5 J) and in small or large groups (Textfig. 5K; P1. 2, fig. 10) in the mesophyll of perianth lobes and sheathing stipules of all
plants.
The vesiculose sclereids may be polygonal or rounded. As a rule they occur in the
mesophyll of leaves of all plants. They also occur in the mesophyll of the sheathing
stipules of Magnolia obovata, M . grandi@ra and Michelia cathcartii. I n the first 2 plants
they are found even in the perianth lobes.
DISCUSSION
The stomatal development in the leaves of all plants studied here is essentially similar
and typically mesogenous. A stomatal meristemoid typically cuts off only 2 subsidiaries
or in addition 1 or 2 encircling cells be repeatedly formed parallel walls on its 2 alternate
sides. There are, however, a few meristemoids in all plants which form 3 intersecting
walls before forming 1 or 2 parallel subsidiaries and the 2 guard cells. These observations
do not completely agree with the account of Paliwal & Bhandari (1962) nor with the
mode of development presumed by Rao (1939). Paliwal & Bhandari have not observed
the formation of any mesogene encircling cells in their material of Magnolia grandiJura
'M . stellata' ( = M . soulangiana) and Michelia champca whereas we t h d that a t least
1 but usually 2-4 mesogene encirclingcells are present inthe stomata of the above species
as well as other plants investigated by us. According to Rao the encircling cells and
subsidiary cells in his Magnoliaceae presumably develop by divisions of the parallel
neighbouring cells (called subsidiary cells) originally cut off by the meristemoid. Subsequently, Bondeson (1952) has actually observed the formation of what might be termed
secondary mesogene encircling cells by divisions of the neighbouring cells in Drimys.
The origin of encircling cells in the stomata of our plants is obviously different although
in some of them the neighbouring cells do divide periclinally to produce secondary
encircling cells.
A second observation of Paliwal & Bhandari (1962) about the haplocheilic nature
of the anomocytic stomata in the perianth lobes of Magnolia grandi$ora, M . stellata
and Michelia chamis also not contirmed. Numerous preparations made from
authentic material of these species coming from various localities (including plants from
the Forest Research Institute Botanical Garden, Debra Dun) clearly show that a vast
majority of perianth stomata develop parallel mesogene subsidiary and encircling cells
in the same manner as the foliar stomata but the stomata of the perianth lobes ultimately
become anomocytic due to the formation of periclinal, anticlinal and oblique partitions
in their parallel mesogene neighbours. It is therefore clear that their development is not
of the haplocheilic type. I n fact, the development of these anomocytic stomata once
again emphasizes the need of observing division figures in the ontogenetic studies of
stomata. Appearances may be deceptive and all anomocytic stomata need not be
perigenous (haplocheilic).
Bondeson (1952) has also observed divisions in the neighbouring perigene cells in the
stomata of Trochodendron and Tetracentrm. Similar divisions were seen but rarely in the
leaves of Magnolia pterocarpa (Text-fig. 5D).
I n having subsidiary cells partially overlapped by the sides of the guard cells the
normal stomata in leaves of all our plants are similar. The same type of stomatal organization has been reported in leaves of Trochodendron and Tetracentrm by Bailey & Nast
Stomata and foliar structure of some Magnoliaceae
275
(1945) and Bondeson (1952) in Illicium, Schisandra and Kadsura by Bailey and Nast
(1948) and in Drimys by Bondeson (1952). The level of guard cells in relation to
subsidiaries has often been regarded as a n important taxonomic character. The cowtancy
of this character in the leaves of all hitherto investigated plants of the magnoliaceous
alliance may support its taxonomic value. On the contrary, the occurrence of stomata
whose guard cells are differently placed in relation to the subsidiary cells in different
parts of the same plant suggest that the value of this character is limited. However, the
character may still be taxonomically useful if the position of the guard cells is considered
in analogous parts.
Other epidermal characters like sinuosities and thickenings in anticlinal walls of cells,
size and form of cells and stomata and distribution of hairs can also be usefully employed
in distinguishing species (see Text-fig. 1A-G; Text-fig. 2A-E). Table 2 shows that the
stomatal frequency and index are in themselves of no great taxonomic value for the
determination of the species of our plants, e.g. the size and form of the leaves and flowers,
etc. of the 2 species of Magnolia g r a n d i F a and M . soulangiana are apparently quite
different but their stomatal frequency, index and even the standard deviation are almost
the same. Therefore, it is obvious that these characters must be considered in conjunction
with other features of the plants.
Table 2. Stomata2frequencies and indices
Stomatal frequency
Species
Range per m m 2
Average per m m 2
Standard deviation
Stomatal index
Magnolia grandijora
185-265
145-317
145-265
185-265
152-291
344-529
278-603
199-384
3 17-529
225
260
210
227
230
408
42 1
316
403
1.7
3.51
2.04
1.5
2.7
3.02
3-6
3.3
4.03
15.7
17.38
14.3
19.76
15.88
19.25
18.18
18.18
18.51
M . pzlmila
M . pteromrpa
M . SOUh?l&?UZ
M . obovata
Michelia oblonga
M . chmpaca
M . fuscata
M . cathcartii
The significance of arrested stomata has already been discussed by Pant (1965a).
The distribution of peculiar rod-like or dumb bell-shaped bodies, oil globules and calcium
oxalate druses in the epidermal cells of various species is also interesting. The rod-like
bodies found in the epidermal cells of Magnolia grandijiora and M . pumila are reported
here for the first time. We are not aware of the existence of any similar epidermal cell
inclusions in other plants of the family. The dumb bell-shaped bodies are comparable
with certain albuminoid grains found in the epidermal and adjacent parenchymatous
cells of species of Schlumbergena and Zygmctus of the Cectaceae (Metcalfe & Chalk,
1950)in the laticifers of 3 species of L a w e a (Guerin, 1923)and in leaves of the sensitive
Oxalidaceae and Leguminosae (Steckbeck, 1919). The last mentioned author has pointed
out that the size of proteinaceous bodies is directly proportional to the sensitivity of leaf
movement in Oxalidaceae but we are unable to assign any significancet o these structures
except for regarding them as possible storage products in the leaves of our Magnoliaceae.
The presence of calcium oxalate druses in the cells of the upper and lower epidermis
of leaves of Magnolia pterocarpa, Michelia champaca and M . cathcartii too is interesting.
The systematic value of these structures can only be determined if a large number of
species of this family are examined.
Florin (1931) has stated that in gymnosperms the haplocheilic stomata are more
primitive than the syndetocheilic ones. While his statement may be true for gymnosperms the same is not true for all vascular plants. The stomata of Equisetum which
admittedly represents an ancient line of pteridophytes are syndetocheilic (Strasburger,
276
DI~YA
DARSW PANT,
F.L.S. AND K n s m LATAGUPTA
1866-7 and Pant and Mehra, 1964). On the other hand primitive plants like Rhynia
possess haplocheilic stomata. Both the types of stomata occur even in the Magnoliales,
e.g. in Xchisandra grandiJLEoa (Jalan, 1962), Troc?w&ndron and Tdracentrm (Bondeson,
1952) the stomata are perigenous (haplocheilic) but they are definitely mesoparacytic
(syndetocheilic) in Drirnys (Bondeson, 1952), Magnolia and Michelia. Occasional presence
of gymnosperm type of thickened lamellae on guard cells o f some species of Michelia
is also interesting but these are seemingly not ligmfied.
SrnNAFiY
The development of stomata and other interesting anatomical features of leaves,
sheathing stipules and perianth lobes of 5 species of Magnolia and 4 species of Michelia
were studied.
Very often the mature foliar stomata are paracytic with 2 parallel subsidiaries and 1or
more parallel encircling cells but the stomata in the sheathing stipules and perianth
lobes are usually anomocytic. A fairly constant feature of the foliar stomata of these
plants is the partial overlapping of the subsidiary cells by the guard cells.
Epidermal cells of a few species contain calcium oxalate druses. In Magnolia grandiflora
and M . pumila the epidermal cells possess peculiar rod-shaped bodies of uncertain chemical
nature.
Polygonal or lobed thick walled brachysclereids occur singly or in groups in the various
investigated species. Thin walled vesiculose sclereids are found in the leaves of all plants
but they are absent in other organs of some species.
The 2 parallel subsidiary cells and encircling cells of stomata develop from the same
initial. The development of stomata is, therefore, typically mesogenous (syndetocheilic).
According to Rao (1939)the encircling cells in some of these plants are formed by divisions
of the subsidiary cells and although this is partly true the encircling cells of a majority
of stomata are formed directly from the stomata1 meristemoids.
According to Paliwal & Bhandari (1962) the anomocytic stomata of the perianth lobes
of Magnolia grandi$ora, M . stellata and Michelia champca are haplocheilic which implies
that they are perigenous. However, we k d that the irregular ring of cells around the
guard cells of stomata in these parts and in the sheathing stipules, develop as a result of
divisions in the mesogene subsidiary cells indicating thereby that these stomata are
mesogenous and their development is essentially similar to that of foliar stomata.
ACKXOWLEDGEMENTS
We are grateful to Professor P. Maheshwari, F.N.I., F.R.S., Chairman of the Biological
Committee of the C.S.I.R., New Delhi for his manifold help and we thank the Council
for financial assistance and for granting a Research Fellowship to the junior author.
Our thanks are due to Dr M. A. Rau, Regional Botanist, Dehra Dun, Mr K. C. Sehni,
Forest Research Institute, Dehra Dun and Dr R. V. Sitholey, Assistant Director, Xational
Botanic Gardens, Lucknow for giving material of some species. We thank Mr H . C. Dubey
(Allahabad University) for collecting material of some of our plants from Darjeeling.
REFERENCES
AFLBER,
E. A. N. 85 PAR-, J., 1907. The origin of angiosperms, J. Linn. SOC.(Bot.), 38: 29-80.
BAILEY,I. W. 8: NAST,C. G., 1945. Morphology and relationships of Trochodendron and Tetracentron.
I. Stem, root and leaf. J. Arnold Arbor., 26: 143-54.
BAILEY,I. W. & NUT, C. G., 1948. Morphology and relationships ofllliciunt, Schisandra and Kadsura.
I. Stem and leaf. J . Arnold Arbor., 29: 77-89.
BESSEY,C. E., 1894. Evolution and classification. Con&. Dep. Bot. Uniw. Xeb., S . S . 7.
BESSEY,C. E., 1915. Phylogenetic taxonomy of flowering plants. Ann. Mo. bot. Card., 2 : 1-155.
Plate 2
Stomata and joliar structure of s m e Magnoliaceue
277
BONDESON,
W., 1952. Entwicklungsgeschichte und Bau der SpaltBfinungen bei den Gattungen
Trochodendron Sieb et Zucc., Tetracentron O h . and Drimys. J. R. et G . Forst. Acta Hort. berg., 16:
169-2 18.
FLORIN,
R., 1931. Untersuchungen zur Stammesgeschichte der Coniferales und Cordiatales, I.
Morphologie und Epidermisstruktur der Assimilationsorgane bei den rezenten Koniferen. K .
Svenska. VetenskAkud. Handl., 10: 1-588.
GUERIX, P., 1923. Les Crtickes: cellules it mucilage laticifbres et canaux s&cri.teurs. BUZZ Soc. bot.
Pr., 70: 125-36, et seq.
HALLIER,H., 1905. Phylogenetic studies of flowering plants. Kew Phyt., 5 : 15562.
HILLIER,H., 1912. L'origine et le syst4me phylktique des angiospermes. Arch. ne'erl. Sci., I11 B, 1:
146-234.
HUTCHIXSOX,
J., 1959. Families offlowering plants, I.Oxford.
JALAN, S., 1962. The ontogeny of st>omatain Schisandra grandifira Hook. f. and Thoms. Phytomorphology, 12: 239-42.
NETCALFE,
C. R.& CHALK, L., 19.50. Anatomy of dicotylehns, I. Oxford.
P A L I ~ A LG.
, S. & BHINDARI, N. S., 1962. Stomata1 development in some Xagnoliaceae. Phytomorphology, 12: 409-12.
P ~ N TD., D., 1965a. O n the ontegeny of stomata and other homologous structures. Plant. Sci.,
Allahabad, 1 : 1-24.
PAST, D. D., 1965b. Indelible clues to stomata1 development in mature epidermis of plants.
Xaturwissen.schujten 5 2 : 481-2.
PANT,
D. D. & MEHRA,B., 1964. Development of stomatainsome fern allies. Proc. vat. Inst. Sci. India,
B 30 ( 2 ) , 1964.
RAO,H. S., 1939. Cuticular studies of Magnoliales. Proc. Indian Acad. Sci., B. 9: 99-116.
STECKBECK,
D. W., 1919. The comparative histology and irritability of sensitive plants. Contrib. bot.,
Lab. Unia. Penn., 4: 185-230.
STRISBURGER,
E., 1886-7. Ein Beitrag zur Entwicklungsgeschichte der Spaltoffnungen. Jb. wiss. Bot.,
5 : 297-342.
TIPPO,O., 1942. d modern classifkation of the plant kingdom. Chron. bot., 7 : 203-6.
YARBROUGH,
J. a,,1934. History of leaf development in Bryophyllum calycinum. Bmer. J . Bot., 22:
467-81.
EXPLASATION OF PLATES
PLATE
1
Fig. 1. Magnolia pumila. Lower epidermis of mature leaf. x 507.
Fig. 2. ,M.grandiflora. Lower epidermis of young leaf with a young completely amphicyclic stoma.
x 1080.
Fig. 3. M . pterocarpn. Lower epidermis of a young leaf with a developing stoma (transitional stage
between the anisocytic and paracytic type of developments). x 1185.
Fig. 4. M . grandijora. Lower epidermis of young leaf showing rod-like bodies in the cells. x 336.
PLATE2
Magnolia grandijora
Fig. 5 . A developing stoma from outer (lower)epidermis of a perianth lobe showing 2 parallel mesogene
neighbouring cells on the right and 1 on the left side of the meristemoid. x 1000.
Fig. 6. Outer epidermis of perianth lobe with a mature stoma (ranunculaceous) with a dividing neighbouring cell. x 1000.
Fig. 7 . Outer epidermis of perianth lobe showing a stoma with a divided subsidiary cell on either side.
x 1000.
Fig. 8. Outer epidermis of perianth lobe showing 2 stomata with undivided subsidiary cells. x 820.
Fig. 9. Outer epidermis of perianth lobe showing a developing stoma whose first mesogene cell is
placed at right angles (vertical in the figure) to the meristemoid and the other 2 mesogene neighbouring
cells. x 1045.
Fig. 10. M . pumila. Transparency of a perianth lobe with groups of polygonal sclereids. x 110.

plants was the origin of plants. These organisms most algae. During

The Art of Public Speaking • Chapter 7

Oracle 12c Data Guard * Far Sync and what*s new

photosynthesis efficiency of date palm varieties grown in saudi arabia