Brazilian Journal of Biological Sciences, 2018, v. 5, No. 10, p. 499-514.
ISSN 2358-2731
https://doi.org/10.21472/bjbs.051026
Taxonomic significance of epidermal and venation
characters in the genus Diospyros L. (Ebenaceae) in
Nigeria
Opeyemi Philips Akinsulire*, Olaniran Temitope Oladipo, Olawale
Abdullahi Abdulraheem, Akinwumi Johnson Akinloye and Herbert
Chukwuma Illoh
Department of Botany. Obafemi Awolowo University. Ile-Ife. Nigeria. *Email:
opeyemiakinsulire@gmail.com.
Abstract. This study investigated the foliar anatomy and
venation patterns of thirteen species of the genus Diospyros in
Nigeria with a view to identifying characters of great taxonomic
value in the genus. Plant collections were made from different
locations in Southwest Nigeria and the site of collection georeferenced with a GPS device. Samples were identified at the
Herbarium of Botany Department, Obafemi Awolowo University
(IFE). Voucher Specimens were deposited in the herbarium and
voucher number assigned to each of the species. The samples
were subjected to foliar epidermal and venation examinations.
Qualitative data were recorded as the quantitative data were
subjected to statistical analysis and the characters vary
significantly (P = 0.05). Epidermal and venation characters
which separate the taxa include stomata type, size and index,
shape and size of epidermal cell, trichome type, presence/
absence of crystal/druses, as well as venation. Paxillate venation
in D. suaveolens is diagnostic for the species. The presence of
parenchymatous sheath over the veins and veinlets in D. tricolor
is a spot character. The study reveals that leaf epidermal and
venation characters are important in delimitation of species in
the genus Diospyros.
Keywords: Classificatory; Diagnostic; Paxillate; Reticulate; Spot
character.
Received
May 29, 2018
Accepted
August 21, 2018
Released
August 31, 2018
Full Text Article
0000-0001-8063-4908
Opeyemi Philips
Akinsulire
0000-0003-2957-2961
Olaniran Temitope
Oladipo
0000-0002-8618-7974
Olawale Abdullahi
Abdulraheem
0000-0003-4256-862X
Akinwumi Johnson
Akinloye
0000-0003-1994-4012
Herbert Chukwuma
Illoh
ISSN 2358-2731/BJBS-2018-0033/5/10/26/499
Braz. J. Biol. Sci.
http://revista.rebibio.net
500
Akinsulire et al.
Introduction
The genus Diospyros belongs to
the family Ebenaceae (Ebony family).
Ebenaceae is pantropical in distribution
with about 500 species (Wallnofer,
2001). They are mainly represented by
trees and shrubs with most species
evergreen, but some are deciduous
(Halle et al., 1978). In the family, leaves
are simple, usually alternate, rarely
opposite to sub opposite or in pseudowhorls of three, spirally or distichously
arranged, petiolate or rarely sub sessile,
induplicate or involutes in bud; stipules
absent; lamina of leaves is coriaceous in
many
species,
less
frequently
chartaceous, pinnately veined; leaf
margins usually entire, very seldom
finely crenulate, usually with strongly
revolute margins at base, at least when
dry; leaf apices spinose in some species.
The Ebenaceous inflorescence is
conventionally referred to as a cyme (Ng,
1991). Solitary flowers are always
terminal on the peduncle. Usually, male
flowers of a given species by far
outnumber
the
females.
The
actinomorphic flowers range from
trimerous, pentamerous to octamerous.
The number of floral parts is known to
vary within species and cannot,
therefore, be used effectively for their
distinctions, as has been done in the past
(Wallnofer, 2001). The fruit is 1-16
seeded multiloculate, usually indehiscent
berries which is subtended by a
persistent 3-8-lobed calyx. White (1983)
posited that fruits of some African
species of Diospyros sect. Royena become
dry, and occasionally tardily dehiscent. In
no species of Ebenaceae, however, is the
fruit completely and spontaneously
dehiscent. Seeds are often dispersed by
various fruit-eating animals, such as civet
cats, monkeys (Tutin et al., 1996).
Ebenaceae are the source of several
economically important products, the
most valuable being their fruits and
timber (ebony) and the genus Diospyros
is best known for producing dense black
wood (ebony) and tasty fruit (e. g.
persimmons and zapotes) (Casper,
2013).
Most of the revisions of the genus
Diospyros have been based on field
observation and macromorphological
characters (Wickremasinghe and Herat,
2006). In view of the complex taxonomic
status in the genus, this study therefore
set out to describe the leaf epidermal
morphology and venation pattern of
thirteen species of the genus Diospyros
with a view to providing useful
additional
information
for
the
delimitation
and
subsequent
identification of members of the genus,
thereby enhancing the taxonomic
revision of the genus. The representative
species
of
the
genus
include
D. undabunda,
D. mespiliformis,
D. iturensis,
D. canaliculata,
D. precatorium,
D. physocalycina,
D. crassiflora, D. tricolor, D. suaveolens,
D. dendo, D. conocarpa, D. nigerica and
D. barteri.
Materials and methods
Study area and target species
The present study was carried
out in south-western Nigeria between
Longitude 2° 31’ and 6° 00’ E and latitude
6° 21’ and 8° 37’ N (Agboola, 1979). The
climate of South-Western Nigeria is
majorly tropical, characterised by wet
and dry seasons with temperature
ranging between 21 °C and 34 °C and
annual rainfall of about 150 mm to
3,000 mm (Faleyimu et al., 2013).
Collection of plants was made from
different locations in Southwest Nigeria
and the site of collection was
georeferenced with a GPS device
(Table 1, Figure 1). Thirteen species
were considered in this study, five
accessions were considered for each
species and ten matured leaves
examined from different parts of the
plants for each of the accessions.
Epidermal study
Sizeable portions from the leaves
of the species studied were taken from
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
standard median portion of the leaf while
the scrape method of Metcalfe (1968)
was used to obtain the epidermis. After
scraping, the scraped portion was
carefully cut and the peels were stained
in Safranin O, rinsed in three to four
changes of water and then mounted in
25% glycerol on a clean glass slide for
light microscopy.
Venation pattern
Sizeable portions of the matured
leaf of each of the species were obtained
from the standard median portion of the
leaf. The materials were decolorized by
boiling in 90% ethanol at 20 °C for about
10-15 min (to remove chlorophyll), then
washed in 3-4 changes of water to
remove all traces of alcohol. The portions
were then transferred to 5% Sodium
Hydroxide and boiled for 30 min for
further decolourization. The materials
were later washed thoroughly to remove
alkaline solution. The partially cleared
501
leaves were further cleared in 5%
domestic bleach (sodium hypochlorite)
for 20-30 min under sunlight The
portions were again washed in 3-4
changes of water, stained in Safranin O
and counter stained in Alcian Blue (to
enhance contrast), rinsed with water (to
remove excess stain) before being
mounted in 25% glycerol on a clean slide
for examination under light microscope.
Data analysis
Data
generated
from
the
documentation were subjected to
Analysis of Variance and Multivariate
Statistical Analysis. Photomicrographs of
all epidermal and venation features were
made with the aid of Accu-scope 33001
LED Trinocular Microscope with 3.2 MP
CMOS Digital Camera. All quantitative
parameters were taken with the aid of
ocular micrometer and final figures
derived with ocular constant.
Table 1. Collection Site, Geographical Coordinates and Voucher Number of Diospyros species
Studied.
Species
Collection site
Geographical
Coordinates
D. barteri
Buffer Forest SNRI, Omo Forest
Reserve, Omo, Ogun State.
IFE 17385
D. canaliculata
Osokun Road, Omo Forest
Reserve, Omo, Ogun State
+ 6° 58′ 44.23′ N
+ 4° 22′ 4.23′ E
D. conocarpa
Buffer Forest SNRI, Omo Forest
Reserve, Omo, Ogun State.
IFE 17389
D. crassiflora
Along the way to Etemi, Omo
Forest Reserve, Omo, Ogun State.
+ 6° 58′ 44.23′ N
+ 4° 22′ 4.23′ E
D. dendo
Buffer Forest SNRI, Omo Forest
Reserve, Omo, Ogun State.
IFE 17386
D. iturensis
Along the way to Etemi, Omo
Forest Reserve, Omo, Ogun State.
+ 6° 58′ 44.23′ N
+ 4° 22′ 4.23′ E
D. mespiliformis
Botany Department, University of
Ibadan, Oyo State
+ 7° 23′ 28.19′ N
+ 3° 54′ 59.99′ E
IFE 17308
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Voucher
Number
+ 6° 51′ 49.14′ N
+ 4° 23′ 42.83′ E
IFE 17387
+ 6° 58′ 19.53′ N
+ 4° 22′ 21.27′ E
IFE 17391
+ 6° 58′ 19.53′ N
+ 4° 22′ 21.27′E
IFE 17315
502
Akinsulire et al.
Table 1. Continued.
Species
Collection site
Geographical
Coordinates
Voucher
Number
D. nigerica
Buffer Forest SNRI, Omo Forest
Reserve, Omo, Ogun State.
IFE 17392
D. physocalycina
Along the way to Etemi, Omo
Forest Reserve, Omo, Ogun
State.
+ 6° 58′ 44.23′ N
+ 4° 22′ 4.23′ E
+ 6° 58′ 19.53′ N
+ 4° 22′ 21.27′ E
IFE 17388
D. precatorium
Osokun Road, Omo Forest
Reserve, Omo, Ogun State
IFE 17616
D. suaveolens
Osokun Road, Omo Forest
Reserve, Omo, Ogun State
+ 6° 51′ 49.14′ N
+ 4° 23′ 42.83′ E
D. tricolor
Botanical Garden, University of
Lagos, Akoka, Lagos State
IFE 17595
D. undabunda
Osokun Road, Omo Forest
Reserve, Omo, Ogun State
+ 6° 30′ 59.99′ N
+ 3° 23′ 5.99′ E
+ 6° 51′ 49.14′ N
+ 4° 23′ 42.83′ E
IFE 17595
+ 6° 51′ 49.14′ N
+ 4° 23′ 42.83′ E
IFE 17384
Figure 1. Map of Nigeria showing Diospyros species distribution.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
Results
Diospyros undabunda
Leaf epidermis and venation
pattern
On the adaxial surface, epidermal
cells are generally polygonal, ranging
from triangular to pentagonal, anticlincal
walls straight to undulating, size varies
between 11.00-15.40 µm long and 4.4011.00 µm wide. Epidermal cell ranges
between 208 and 242 mm-², stomata are
absent (Figure 2A). On the abaxial
surface, epidermal cells ranges from
triangular to pentagonal with wavy
anticlinal
walls,
anticlinal
walls
sometimes straight, epidermal cell size
ranges between 11.00-24.60 µm long and
6.60-19.80 µm wide, epidermal cell
ranges between 112 to 130mm-²,
stomata type is cyclocytic, guard cell
mostly circular occasionally elliptic,
mean stomata size 67.0 ± 2.8 µm long
and 47.0 ± 2.0 µm wide, stomata
frequency 10-15 mm-², mean stomata
index is 10.45% (Figure 3A). On the
veins, venation is regular polygonal
reticulate, areoles are well developed,
shape ranges from triangular to
pentagonal, size about 200.20-582.40 µm
long and 127.40-382.20 µm wide. Veins
are simple, curved or branched,
occasionally forked, vein density 0-4 per
areole (Figure 4A)
Diospyros mespiliformis
Leaf epidermis and venation
pattern
Epidermal cells are largely
irregular on the adaxial surface,
anticlinal walls sinuous, cells about twice
longer than wide, size ranges between
13.20-22.00 µm long and 6.60-13.20 µm
wide, epidermal cell number ranges
between 186 to 212 mm-²; stomata are
absent (Figure 2B). On the abaxial
surface, epidermal cells are irregular,
anticlinal wall is sinuous, cells about
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
503
twice longer than wide, cell size ranges
from 13.20 – 24.20 µm long and 6.6013.20 µm wide, epidermal cell number
ranges between 152 to 176 mm-²,
stomata type is paracytic, guard cell
mostly circular and occasionally elliptic,
stomata frequency around 11-18 mm-²,
mean stomata size about 77.0 ± 2.1 µm
long to 54.0 ± 1.5 µm wide, mean
stomata index is 9.04% (Figure 3B). On
the veins, venation is regular polygonal
reticulate, areoles are well developed,
shape largely polygonal, sometimes
irregular, size ranges from 245.70764.40 µm long and 145.60-527.80 µm
wide; veins simple; branched and
occasionally forked; vein density 0-3 per
areole (Figure 4B).
Diospyros canaliculata
Leaf epidermis and venation
pattern
Epidermal cells are irregular,
anticlinal walls are wavy with variable
sizes, ranging from 8.80-15.40 µm long to
6.60-11.00 µm wide, epidermal cell
number also varies between 211-229
cells mm-², stomata absent (Figure 2C).
On the abaxial surface, epidermal cells
are predominantly irregular with wavy
anticlinal walls, cells variable in size,
ranging from 11.00-17.60 µm long to
6.60-11.00 µm wide, epidermal cell
number ranges between 160-187 mm²;
stomata staurocytic, stomata frequency
about 28-38 per mm²; mean stomata size
is 66.0 ± 2.1 µm long and 46.0 ± 1.9 µm
wide, mean stomata index up to 13.73%,
guard cell are mostly circular (Figure
3C). On the veins, venation is regular
polygonal reticulate, areoles well
developed, shape ranges from triangular
to pentagonal, size ranges from 282.10773.50 µm long to 182.00-491.40 µm
wide; veins simple and branched;
occasionally forked; 0-2 per areole
(Figure 4C).
504
Akinsulire et al.
Figura 2. Photomicrograph of Adaxial Surfaces of Thirteen species of Diospyros. EC=Epidermal Cell,
A= D. undabunda, B= D. mespiliformis, C= D. iturensis, D= D. canaliculata, E= D. precatorium, F=
D. physocalycina, G = D. crassiflora, H= D. tricolor, I= D. suaveolens, J= D. dendo, K= D. conocarpa, L=
D. nigerica, M= D. barteri.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
505
Figure 3. Photomicrograph of Abaxial Surfaces of Thirteen species of Diospyros. EC = Epidermal
Cell, CST = Cyclocytic Stomata, PST = Paracytic Stomata, SST = Staurocytic Stomatata, AST =
Anomocytic Stomata, SC = Scale. A = D. undabunda, B = D. mespiliformis, C = D. iturensis, D = D.
canaliculata, E = D. precatorium, F = D. physocalycina, G = D. crassiflora, H = D. tricolor, I = D.
suaveolens, J = D. dendo, K = D. conocarpa, L = D. nigerica, M = D. barteri.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
506
Akinsulire et al.
Figure 4. Photomicrograph of Venation Pattern of Thirteen species of Diospyros. AR = Areole, V =
Vein, MV = Main Vein, PSH = Parenchymatous Sheath, DR = Druses, A = D. undabunda, B = D.
mespiliformis, C = D. iturensis, D = D. canaliculata, E = D. precatorium, F = D. physocalycina, G = D.
crassiflora, H = D. tricolor, I = D. suaveolens, J = D. dendo, K = D. conocarpa, L = D. nigerica, M = D.
barteri.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
Diospyros iturensis
Leaf epidermis and venation
pattern
Epidermal
cells
mostly
rectangular, anticlinal walls straight to
undulating, epidermal cell number
ranges between 188-208 mm², size
ranges between 13.20-22.00 µm long and
6.60-13.20 µm wide; stomata absent
(Figure 2D). On the abaxial surface,
epidermal cells generally polygonal,
anticlinal walls wavy to undulating, size
ranges between 13.20-26.40 µm long and
8.80-15.40 µm wide; epidermal cell
number ranges between 128 and 168
mm²; stomata type largely cyclocytic;
guard cell is mostly elliptic, mean
stomata size 67.0 ± 1.9 µm long and
49.0 ± 2.0 µm wide, stomata frequency
11-15 mm²; mean stomata index is
7.28% (Figure 3D). On the veins,
venation is regular polygonal reticulate,
areoles well developed, sometimes
irregular, size ranges from 291.20709.80 µm long and 136.50-382.20 µm
wide; veins simple; branched and forked;
vein density 0-4 per areole (Figure 4D).
Diospyros precatorium
Leaf epidermis and venation
pattern
Epidermal
cells
generally
polygonal on the adaxial surface,
anticlinal wall straight to slightly wavy,
cell varies in size ranging between11.0013.25 µm long and 17.60-18.09 µm wide;
epidermal cell number ranges between
210 to 232 mm2, stomata absent (Figure
2E). On the abaxial, epidermal cells
generally polygonal, anticlinal walls
wavy to sinuous, size ranging between
13.20-26.40 µm long and 8.80-11.00 µm
wide; epidermal cell number varies from
161-188 per mm², stomata type is
paracytic, mean stomata size is 63.0 ± 1.8
µm long and 44.0 ± 1.9 µm wide, stomata
frequency 32-43 mm², mean stomata
index 17.21%, guard cell elliptic (Figure
3E). On the veins, venation is regular
polygonal reticulate, Areoles well
developed; shape generally polygonal,
size ranges from 354.90-755.30 µm long
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
507
to 172.90-482.30 µm wide; veins simple,
branched and occasionally forked; vein
density 0-6 per areole (Figure 4E).
Diospyros physocalycina
Leaf Epidermis and Venation
Study
On the adaxial surface, epidermal
cell are largely irregular, anticlinal wall is
sinuous, cell size ranges between 11.0015.40 µm long and 6.60-11.00 µm wide,
epidermal cell number ranges between
184 and 208 cells mm2, stomata are
absent on the adaxial surface (Figure 2F).
On the abaxial surface, epidermal cells
are largely irregular, anticlinal walls
sinuous, size ranges between 15.4026.40 µm long and 11.00-19.80 µm wide,
Epidermal cell number ranges between
110-132 mm2, stomata type is
anomocytic, stomata frequency 10-17
mm², mean stomata size is 61.0 ± 1.70
µm long and 36.0 ± 1.70 µm wide, mean
stomata index is 11.76%, guard cell
elliptic (Figure 3F). On the veins,
venation is regular polygonal reticulate,
areoles perfectly formed, shape mostly
polygonal, size ranges between 245.70728.00 µm long and 109.20-309.40 µm
wide; veins mostly forked, occasionally
simple linear, vein density is 0-3 per
areole (Figure 4F).
Diospyros crassiflora
Leaf epidermis and venation
study
On the adaxial surface, epidermal
cells are rectangular to pentagonal with
straight to undulating anticlinal walls,
size ranges between 11.00-17.60 µm
long and 6.60-11.00 µm wide, epidermal
cell number varies between 204-232
cells mm2, stomata absent (Figure 2G).
On the abaxial, epidermal cell are largely
polygonal, anticlinal wall straight slightly
wavy, size 11.00-19.80 µm long and 6.6013.20 µm wide, epidermal cell number
75-92 mm², stomata cyclocytic, guard
cell elliptic, mean stomata size is
65.0 ± 1.8 µm long and 46.0 ± 1.3 µm
wide, stomata frequency 7-12 mm2,
mean stomata index is 9.80% (Figure
508
Akinsulire et al.
3G). On the veins, venation is regular
polygonal reticulate, areoles well
developed, largely polygonal, size ranges
from 218.40-691.60 µm long and 109.20391.30 µm wide, veins is simple,
branched and occasionally forked, vein
density is 0-3 per areole (Figure 4G).
Diospyros tricolor
Leaf epidermis and venation
pattern
On the adaxial surface, epidermal
cells are polygonal, mostly pentagonal,
anticlinal wall straight to undulating, size
ranges between 8.80-17.60 µm long and
6.60-11.00 µm wide; epidermal cell
number ranges between 200-224 mm2,
stomata absent (Figure 2H). On the
abaxial surface, epidermal cells are
polygonal, mostly pentagonal, anticlinal
walls straight to undulating, cells
variable in size, ranging from 11.0017.60 µm long and 6.60-11.00 µm wide,
epidermal cell number about 120-136
mm2, stomata cyclocytic, guard cells
elliptic, mean stomata size is 57.0 ± 1.5
µm long and 40.0 ± 1.2 µm wide, stomata
frequency 10-14 mm2, mean stomata
index is 9.03% (Figure 3H). On the veins,
venation is regular polygonal reticulate,
areoles well develop, size ranges from
182.00-464.10 µm long and 100.1263.90 µm wide, veins mostly simple,
occasionally forked or linear, vein
density 0-2 per areole. Parenchymatous
sheath surround veins and veinlets
(Figure 4H).
Diospyros suaveolens
Leaf epidermis and venation
study
Epidermal
cell
largely
rectangular to hexagonal, anticlinal walls
straight to undulating, size variable,
ranging from 8.80-13.20 µm long and
6.60-8.80 µm wide, epidermal cell ranges
between 274-304 mm2, stomata absent
(Figure 2I). On the abaxial, epidermal
cells are largely rectangular, occasionally
irregular, anticlinal walls straight to
undulating, size ranges from13.20-26.40
µm long and 8.80-15.40 µm wide,
epidermal cell varies from 161-184 per
mm2, stomata type is cyclocytic with
elliptic guard cell, stomata frequency
about 10-13 per mm2, mean stomata size
is 67.0 ± 2.0 µm long and 50.0 ± 1.9 µm
wide, mean stomata index is 6.45%
(Figure 3I). On the veins, venation is
paxillate, Areoles is imperfect, occurring
in oriented fields, shape ranges from
triangular to pentagonal, size ranges
from 191.10-518.70 µm long and 100.10245.70 µm wide, veins mostly linear, vein
density 0-2 per areoles; druses present
in the areoles (Figure 4I).
Diospyros dendo
Leaf epidermis and venation
study
On the adaxial surface, epidermal
cells are largely irregular with deeply
sinuous anticlinal walls, size ranges
between 15.40-19.80 µm long and 8.8015.40 µm wide, epidermal cell number
ranges between 161-189 per mm2,
stomata absent (Figure 2J). On the
abaxial surface, epidermal cells are
irregular with wavy anticlinal walls, size
ranges between13.20-22.00 µm long and
6.60-13.20 µm wide, epidermal cell
number about 117-134 mm2, stomata
anomocytic, mean stomata size is
56.0 ± 1.5 µm long and 37.0 ± 1.5 µm
wide, mean stomata index 7.81%,
stomata frequency 9-13 mm2, scales
present, trichome frequency 0-5 mm2
(Figure 3J). On the veins, venation is
regular polygonal reticulate, areoles
moderately developed, shape ranges
from triangular to pentagonal, size
ranges from 309.40-873.60 µm long and
191.10-482.30 µm wide, veinlet ending
simple, branched and occasionally
forked, vein density is 0-2 per areole
(Figure 4J).
Diospyros conocarpa
Leaf epidermis and venation
pattern
On the adaxial surface, epidermal
cells are largely irregular with deeply
sinuous anticlinal walls, size ranging
between 17.60-24.20 µm long and 6.60-
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
13.20 µm wide, epidermal cell number
ranges between 231-249 mm2, stomata
are absent (Figure 2K). On the abaxial,
epidermal cells are irregular, anticlinal
walls are wavy or slightly sinuous, size
ranges between11.00-26.40 µm long and
6.60-19.80 µm wide, epidermal cell
number 120-138 mm2, stomata is
staurocytic, guard cells are elliptic, mean
stomata size about 69.0 ± 1.4 µm long
and 44.0 ± 1.7 µm wide, mean stomata
index 10.49%, stomata frequency 12-18
mm2,
scales
present,
trichomes
frequency 0-6 per field (Figure 3K). On
the veins, venation is regular polygonal
reticulate, areoles are well developed,
shape ranges from triangular to
pentagonal, 318.5-819.00 µm long and
154.70-382.20 µm wide, veins are
simple, occasionally forked, vein density
0-3 per areole (Figure 4K)
Diospyros nigerica
Leaf epidermis and venation
pattern
On the adaxial surface, epidermal
cells are irregular, with deeply sinuous
anticlinal walls, size ranging between
17.60-22.00 µm long and 8.80-13.20 µm
wide, epidermal cell number ranges
between 140-159 mm2, stomata absent
(Figure 2L). On the abaxial surface,
epidermal cells are irregular, anticlinal
walls sinuous, sometimes wavy, size
ranges between13.20-19.80 µm long and
8.80-13.20 µm wide, epidermal cell
number 122-133 mm2; stomata largely
cyclocytic, guard cell is elliptic, mean
stomata size is 64.0 ± 1.9 µm long and
40.0 ± 2.5 µm wide, stomata frequency
12-16 mm2, mean stomata index is
9.52% (Figure 3L). On the veins,
venation is dichotomizing, areoles well
developed, shape largely rectangular to
hexagonal, size ranges between 291.20718.90 µm long and 136.80-427.70 µm
wide, veins are simple branched and
occasionally forked, vein density 0-2 per
areole (Figure 4L).
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
509
Diospyros barteri
Leaf epidermis and venation
pattern
On the adaxial surface, epidermal
cells are polygonal, anticlinal walls
straight to undulating, epidermal cell
number ranges between 221-240 per
mm2; size ranges between 19.80-24.20
µm long and 8.80-11.00 µm wide,
stomata absent (Figure 2M). On the
abaxial surface, epidermal cells are
polygonal with straight to undulating
anticlinal walls, size ranges between
11.00-26.40 µm long and 8.00-15.40 µm
wide, epidermal cell number 162-186
mm2; stomata largely cyclocytic, guard
cells are mostly elliptic, mean stomata
size is 56.0 ± 1.7 µm long and 41.0 ± 1.7
µm wide, stomata frequency 10-13 mm2,
mean stomata index is 5.88% (Figure
3M). On the veins, venation is regular
polygonal reticulate, areoles well
developed, shape ranges from triangular
to pentagonal, size ranges from 227.50673.40 µm long and 145.60-500.50 µm
wide, veins mostly linear, vein density 02 per areole, druses are present and
numerous (Figure 4M).
Discussion
Foliar Epidermal Morphology
and Venation Pattern
Leaves in the taxa studied are
generally hypostomatic and it is
considered a character of unification in
the genus, hence their generic
classification. However, while this
finding contradicts the work of Ng
(1971), who reported that stomata can
be found on both surface of the leaf in D.
mespiliformis, it corroborates Schadel &
Dickson (1979) who pointed out that
stomata are usually anomocytic and
occur only on abaxial leaf surfaces in
genus Diospyros. On the adaxial surfaces
of all the taxa, sinuous anticlinal walls
can be used in grouping D. mespiliformis,
510
Akinsulire et al.
D. physocalicina, D. dendo, D. conocrpa
and D. nigerica (Figure 2B, F, J, K and L)
while the anticlinal walls of all other
species ranges from straight to wavy
(Figure 2A, C, D, E, G, H, I and M).
However, on the abaxial surfaces,
D. mespiliformis,
D. precatorium,
D. physocalicina,
D. conocarpa
and
D. nigerica can be classified on the
account of slightly sinuous to sinuous
anticlinal walls (Figure 3B, E, F, K and L).
Significant variations exist on both the
type of stomata and distribution in the
genus studied. The species can be
grouped into four on the account of the
type of stomata present. D. physocalycina
and D. dendo are classified by anomocytic
stomata on the abaxial surface (Figure 3F
and I). This observation is also in line
with Schadel and Dickson (1979).
D. canaliculata and D. conocarpa are
grouped by staurocytic stomata (Figure
3C and K), while D. mespiliformis and D.
precatorium are characterized by
paracytic stomata (Figure 3B and E),
hence classificatory for the species. Other
species as D. undabunda, D. iturensis, D.
crassiflora, D. tricolor, D. suaveolens, D.
nigerica and D. barteri are classified by
cyclocytic stomata (Figure 3A, D, G, H, J, L
and M). However, the presence of
cyclocytic stomata in some species of
Diospyros has previously been reported
by Stace (1965) and Wallnofer (2001)
who both posited that some species in
the genus Diospyros possess cyclocytic
stomata and that their subsidiary cells
differ somewhat in shape, size and
orientation, and in having straight
anticlinal walls. The quantitative foliar
epidermal character of D. mespliformis
shows a significant longer and wider
stomata length and width as D. dendo
possesses the least, D. precatorium also
has the highest stomata density with D.
crassiflora having the least hence
separating the species (Table 2). The
influence of trichome morphology and
distribution in the taxonomy of different
groups of plants has been well
documented by Adedeji et al. (2007) in
the delimitation of genera and species
within the family Solanaceae. Rammaya
and Rao (1976) and Rao and Rammaya
(1977) have also emphasized the
taxonomic importance of trichomes in
the family Malvaceae. In this study, the
presence of scales on the abaxial surfaces
of D. dendo and D. conocarpa is
classificatory for the two species (Figure
3J and K). This reflects their level of
closeness and monophyletic origin. The
presence of scales in the two species
aligns with the report of Wallnofer
(2001) who reported that scale hairs are
present on some African species of
Ebenaceae.
Foliar venation has proven to be
useful in delimitation of species (Levin
1986a). Leaf venation among many other
characters of leaf is considerably
different in each species, though constant
among members of the same species
(Provance and Sanders, 2006). In this
study, irregular as well as welldeveloped triangular to polygonal
areolation pattern which are peculiar
and prominent in all the species studied
suggests a generic character. The
presence of 0 - 6 vein density per areole
in D. precatorium is a spot character for
the species (Figure 4E). The imperfect
areole in D. suaveolens (Figure 4I) is
diagnostic for the species as all others
possess perfect areoles. The species can
be grouped into two on the basis of their
nature of veins and veinlets: Simple or
unbranched veinlets found in D.
suaveolens and D. barteri is classificatory
(Figure 4I and M) while branched
veinlets found in the rest of the taxa can
be used in grouping them. D. dendo is
distinctly separated from the rest of the
species by the possession of significantly
longer and wider areole (Table 3). On the
contrary D. suaveolens is uniquely
delineated from other species by the
possession of significantly smaller areole
size (Table 3). The occurrence of
numerous druses in the areoles of D.
suaveolens and D. barteri classifies the
taxa and indicates a level of taxonomic
relationship between the two species
(Figure 4I and M). Meanwhile, the
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
importance of crystals in taxonomy has
been highlighted by many scientists
including Amos (1951) as well as Illoh
and Inyang (1998). Ter Welle (1976) also
emphasized that the mode of distribution
of crystals is also an important
taxonomic tool. The presence of
parenchymatous sheath only in D.
tricolor (Figure 4H), as well as paxillate
venation in D. suaveolens (Figure 4I) (as
other species are grouped by their
regular polygonal reticulate venation)
are diagnostic for the species and are of
great taxonomic value. The dendogram
of the species (Figure 5) revealed that D.
mespiliformis and D. canaliculata as well
as D. physocalicina and D. conocarpa are
classified to the highest level of similarity
as every other members of the genus
(except D. undabunda) shared some
generic relationship with them indicating
they are recently evolved. However, D.
undabunda is very distant to every other
511
taxa hence its primitiveness. The
similarity observed in D. mespiliformis
and D. canaliculata as well as D.
physocalicina and D. conocarpa is evident
in their quantitative epidermal and
venation characters and common
ancestry. The PCA scattered diagram
(Figure 6) revealed the similarities in the
genus. It clustered the species into two
groups on the basis of their similarity
and differences. The closeness observed
between D. iturensis, D. nigerica, D.
conocarpa, D. crassiflora and D. bateri
and D. canaliculata as well as D.
precatorium, D. canaliculata and D.
mespiliformis is a function of the
similarities in their leaf and venation
taxonomic characters. This study
therefore reveals that foliar epidermal
and venation characters are important in
delimitation of species in the genus
Diospyros and should be used as basis for
taxonomy.
Table 2. Foliar epidermal characters (abaxial and adaxial surfaces) of thirteen species of Diospyros
with Duncan Multiple Range Test.
NEC
D. undabunda
D. mespiliformis
D. iturensis
D. canaliculata
D. precatorium
D. physocalycina
D. crassiflora
D. tricolor
D. suaveolens
D. dendo
D. conocarpa
D. nigerica
D. barteri
222.5d
199.2g
196.7g
219.4e
222.5de
197.2g
219.4e
211.3f
292.1a
179.1h
239.1b
151.6i
231.9c
Adaxial
ECL
(µm)
129.9fg
18.6bc
16.7d
12.0g
15.0e
12.6g
14.5e
13.9ef
11.9g
17.6cd
19.6b
19.6b
21.7a
ECW
(µm)
7.8e
9.0cd
10.7ab
7.9de
8.3de
8.8de
8.4de
9.0cd
7.9de
11.3a
10.3ab
11.4a
10.0bc
SD
13.8ed
15.1c
12.7ef
30.5b
40.6a
14.2cd
9.4h
11.8fg
11.2g
11.1g
15.3c
13.7de
11.5g
SL
(µm)
67.3b
76.9a
66.8bc
64.8bc
63.7bc
61.4cd
65.1bc
57.3de
67.3b
55.5e
64.2bc
69.2b
56.4de
SW
(µm)
47.3bc
54.1a
49.4ab
46.3bc
43.6cde
37.1f
45.5bcd
40.0ef
49.6ab
37.3f
39.6ef
43.7cde
40.9def
Abaxial
NEC
121.7e
163.9b
128.1d
174.5a
175.1a
121.9e
83.7f
125.5d
172.6a
125.5de
125.7de
128.1d
176.3a
ECL
(µm)
18.6b
18.0bc
18.4b
13.3f
14.5ef
20.9a
15.3def
14.6ef
18.4b
17.2bcd
17.2bcd
15.9cde
166.3bcde
ECW
(µm)
13.9a
9.6cde
10.7bcd
8.9e
9.6cde
14.2a
9.9cde
9.0de
10.9bc
10.3bcde
11.8b
10.0cde
10.5bcde
*means with the same alphabet along the same column are not significantly different. SDStomata Density, SL- Stomata Length, SW- Stomata Width, NEC – Number of Epidermal Cells, ECL –
Epidermal Cells Length, ECW – Epidermal cell Width.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
512
Akinsulire et al.
Table 3. Quantitative parameters of venation pattern in thirteen species of Diospyros with Duncan
Multiple Range Test.
D. undabunda
D. mespiliformis
D. iturensis
D. canaliculata
D. precatorium
D. physocalycina
D. crassiflora
D. tricolor
D. suaveolens
D. dendo
D. conocarpa
D. nigerica
D. barteri
Areole length (µm)
289.8e
549.2bc
546.8bc
583.9ab
488.2bc
458.9cd
511.4bc
289.8e
287.1e
640.6a
579.2ab
495.9bc
482.8c
Areole width (µm)
190.2ef
278.5abc
226.2cde
295.6ab
256.1bcd
218.7de
244.8bcd
151.1fg
129.7g
314.9a
256.6bcd
251.6bcd
249.8bcd
Vein density
0-4
0-3
0-4
0-2
0-6
0-3
0-3
0-2
0-2
0-2
0-3
0-2
0-2
*Means with the same alphabet along the same column are not significantly different.
Figure 5. Dendogram of Diospyros species obtained by cluster analysis based on quantitative foliar
epidermal and venation characters.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
Epidermal and venation characters in the genus Diospyros
513
Figure 6. Cluster analysis of Diospyros species based on quantitative foliar epidermal and venation
characters.
Conclusion
Acknowledgement
This study concluded that foliar
epidermis and venation characters are
important in the taxonomy of the genus
Diospyros. It has revealed additional
information for the delimitation and
subsequent identification of members of
the genus, thereby enhancing the
taxonomic revision of the genus.
The authors wish to acknowledge
Mr Abiodun Omole, of the Histology
Laboratory, Department of Botany,
Obafemi Awolowo University, Ile-Ife for
the technical assistance rendered.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.
514
Akinsulire et al.
Conflict of interest
The authors have declared that
there is no conflict of interest.
References
Adedeji, O. A.; Ajuwon, O.Y.; Babawale, O.
Foliar Epidermal Studies, Organographic
distribution and taxonomic importance of
trichomes in the Family Solanaceae.
International Journal of Botany, v. 3, no. 3,
p. 276-282, 2007.
Agboola, S. A. An Agricultural Atlas of
Nigeria. Nigeria: Oxford University Press,
1979.
Amos, G. Some siliceous timbers of British
Guyana. Carribbean, v. 12, p. 133-137, 1951.
Carlquist, S. Comparative Plant Anatomy.
New York: Holt, Rinehart and Winston, 1961.
Casper, T. H. Population genetics and
ethnobotany of cultivated Diospyros riojae
Gómez Pompa (Ebenaceae), an endangered
fruit crop from Mexico. Genetic Resources
Crop Evolution, v. 60, p. 2171-2182, 2013.
https://doi.org/10.1007/s10722-0130015-z
Faleyimu, O. I.; Agbeja, B. O.; Akinyemi, O.
State of forest regeneration in Southwest
Nigeria. African Journal of Agricultural
Research, v. 8, no. 26, p. 3381-3383, 2013.
Halle, F.; Oldeman, R. A. A.; Tomlinson, P. B.
Tropical Trees and Forests. Berlin:
Springer Verlag, 1978.
Illoh. H. C.; Inyang, U. E. Foliar epidermis and
petiole anatomy in some Nigerian Solanum
Linn. species in the sub-genus Leptostemon
(Bitt.) Dun. Glimpses in Plant Research,
v. 12, p. 73-86, 1998.
Levin, G. A. Systematic foliar morphology of
Phyllanthoideae
(Euphorbiaceae).
1.
Conspectus Saint Ann. Missouri Botanical
Garden, v. 73, p. 86-98, 1986.
Metcalfe, C. R. Current development in
Systematic Plant Anatomy. In: Heywood, V. H.
(Ed.). Modern Methods in plant taxonomy.
London: Academy Press, 1968. p. 45-57.
Ng, F. S. P. A taxonomic study of the
Ebenaceae with special reference to
Malesia. Oxford, UK: University of Oxford,
1971. (Ph. D. Thesis).
Ng, F. S. P. The relationships of the
Sapotaceae within the Ebenales. In:
Pennington, T. D. (Ed.). The genera of
Sapotaceae. Kew, UK: Royal Botanic
Gardens, 1991
Provance, M. C.; Sanders, A. C. More American
black sapotes: New Diospyros (Ebenaceae)
for Mexico and Central America. Sida, v. 22,
p. 277-304, 2006.
Rammaya, N.; Rao, R. S. Morphology phylesis
and Biology of the peltate scale, stellate and
tufted hairs in some Malvaceae. Journal of
Indian Botanical Society, v. 55, p. 75-79,
1976.
Rao, R. S.; Rammaya, N. Structure distribution
and taxonomic importance of trichomes in
the
Indian
species
of
Malvastrum.
Phytomorphology, v. 27, p. 40-44, 1977.
Schadel, W. E.; Dickison, W. C. Leaf anatomy
and venation patterns of the genus Diospyros.
Journal Arnold Arbor, v. 60, p. 8-37, 1979.
Stace, C. A. Cuticular studies as an aid to plant
taxonomy. Bulletin British Museum (Nat.
Hist.), Botany, v. 4, p. 1-78, 1965.
Ter Welle, B. J. H. Silica grains in woody
plants in Neotropics especially Surinam. Leid
Botanist. Ser., v. 3, p. 107-142, 1976.
Tutin, C. E. G.; Parnell, R. J.; White, F.
Protecting seeds from Primates: Examples
from Diospyros spp. in the Lopé Reserve,
Gabon. Journal Tropical Ecology, v. 12,
p. 371-384, 1996.
Wallnofer, B. The Biology and Systematics of
Ebenaceae: A review. Annalen des
Naturhistorischen Museums in Wien, B,
v. 103, p. 485-512, 2001.
White, F. Ebenaceae. Fl. Zambesiaca, v. 7, no.
1, p. 248-300, 1983.
License information: This is an open-access article distributed under the terms of the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
Braz. J. Biol. Sci., 2018, v. 5, No. 10, p. 499-514.