epidermal micromorphology of species in the genus ...

JPCS Vol(3) ● Oct-Dec 2011 

www.arpapress.com/Volumes/JPCS/Vol3/JPCS_3_04.pdf 

EPIDERMAL MICROMORPHOLOGY OF SPECIES IN THE GENUS 

CRASSOCEPHALUM MOENCH .S. MOORE (COMPOSITAE) IN 

NIGERIA 

Kemka, C.I. 1 & Nwachukwu, C.U. 2 

Department of Biology, Alvan Ikoku Federal College of Education Owerri, Imo State, Nigeria 

ABSTRACT 

Detailed studies on eight Crassocophalum species ( biafrae, C. montuosum, C. mannii, C. crepidioides C. 

vitellinum, C. rubens, C.togoense and C. sarcobasis) found in Nigeria, which are important leaf vegetables were 

undertaken with the aid of a microscope to ascertain their taxonomic relationship. The micromorphological features 

discovered include the hypostomatic distribution of stomata in C. mannii while the other species had 

hypoamphistomatic. Sinuous anticlinal wall was present on adaxial (upper) surfaces of C. togoense and 

C.crepidioides, the clusters of trichomes on mid-vein of the adaxial surfaces of C.vitellinum and C. 

crepidioides.The high density of trichomes on the veins of the adaxial surface of C.mannii is of taxonomic interest 

and could be used to demilit the taxon from the other species. C.vitellinum, C.crepidioides and C. togoense which 

are densely hairy could also be delimited from C.biafrae and C.montuosum that are sparsely hairy.A mixture of 

sinuous and straight-arcuate anticlinal wall was present in both the abaxial and adaxial surfaces of all 

crassocephalum species studied except in C.togoense and C.crepidioides that has sinuous anticlinal wall in both 

adaxial and abaxial surfaces. 

Keywords. Crassocephalum , Micromorphology, Epidermis,Adaxial,Abaxial. 

1. INTRODUCTION 

The genus Crassocephulum Moench S. Moore is a member of the tribe Senecioneae in Compositae (Asteraceae) 

family. The family is cosmopolitan in distribution and in West Africa contains about 84 genera and 288 species 

(Gill, 1988). The members of the genera are mostly herbs and rarely shrubs. Crassocephalum is represented by 

twenty four species in Tropical Africa ( Bosch, 2004 ) and fifteen species in West Africa in which ten species have 

been recorded in Nigeria (Hutchinson and Dalziel, 1963). Crassocephalum, which is in the same tribe as Emilia, 

have their involucral bracts being in only one series (Olorode, 1984).The species of the genus Crassocephalum are 

of various economic values. C. crepidioides is a herb often cultivated in Sourthern Nigeria and are used as 

vegetables. In Kenya donkeys are reported to browse C. montuosum and in (Tanganyika) Tanzania the plant is used 

for treating infected eyes.The importance of epidermal characters in general and those of trichome in particular has 

been widely recognized in angiospermic taxonomic consideration by workers such as (Ogundipe, 

1992),(Nwachukwu and Edeoga, 2006) in eight species of Indigofera Leguminosae- Papilionideae. (Mbagwu, 

Nwachukwu and Okoro, 2008) in two species of Solanum (Solanaceae),(Edeoga and Ikem 2001) in three species of 

Boerhevia (Nyctaginaceae). According to them majority of the flowering plants can readily be identified with as 

much ease by their vegetative characters as by their floral structure.Considering the various uses of Crassocephalum 

plants and the paucity of information on the epidermal studies, this paper therefore describes the epidermal 

micromorphological characters of species in the genus Crassocephalum 

2. MATERIALS AND METHODS 

Fresh and mature leaves were collected from randomly selected plants of species studied. The specimens were fixed 

in F.A.A. (formalin acetic acid alcohol mixture) for 48 hours to ensure that the cells are possibly maintained as near 

to life and improve the contrast. Herbarium materials were first boiled for about 10 minutes to soften it before fixing 

them. After 48 hours the fixed materials were rinsed with distilled water and soaked in 5% commercial bleach 

(Sodium Oxochlorate II (Nacl) for about 20 minutes to lubricate and soften the tissues of the leaves. The surface to 

be examined was placed on a glass slide while the other surface was carefully scraped with a razor blade. The clear 

epidermal layers obtained were then washed in several changes of distilled water, stained in 1% safranin – 0 for 

about 1 minute and temporary mounted in aqueous glycerol solution. 

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Kemka & Nwachukwu ● Species in the Genus Crassocephalum 

3. RESULTS 

The epidermal cell and stomatal characteristics of the taxa investigated are shown in Tables 1 and 2. The taxa 

studied showed sinuous anticlinal walls on all the abaxial surfaces. (Plates 9,10,11,12,13,and 14). Sinuous anticlinal 

wall also occurred on the adaxial surfaces of C. togoense and C. crepidioides (Plates 3 and 8). The anticlinal wall is 

straight to arcuate on the adaxial surfaces of C. mannii, C. biafrae, C. vitellinum, C. montuosum and C. crepidioides 

(Plates 1, 2, 3, 4, 5, 6, 7 and 8). 

Cuticular striations appeared on the abaxial surfaces of C. montuosum C. vitellinum and C. crepidioides. There are 

four to five epidermal cells around the stomata on both the adaxial and abaxial surfaces in all the species studied. 

The distribution of the stomata is hypoamphistomatic in all the species except C. mannii which is hypostomatic. 

Contiguous stomata were found in the abaxial and adaxial surface of all the taxa studied viz. C. biafrae, C. 

montuosum, C. mannii, C. crepidioides C. vitellinum, C. rubens, C.togoense and C. sarcobasis. Anomocytic stomata 

were found on both adaxial and abaxial surfaces of all the species studied. Anisocytic stomata were found on the 

adaxial surface of C. vitellinum, C. biafrae and C. sarcobasis. 

TRICHOMES: 

Simple unbranched, non glandular trichomes occurred on all the taxa studied. The occurrence is more on the abaxial 

surfaces than the adaxial surface. The mid-vein of the adaxial surfaces of C. mannii showed clusters of these simple 

unbranched non-glandular trichomes. In terms of density of the trichomes, the results indicated that C. vitellinum, C. 

crepidioides, C. sarcobasis and C. togoense are densely hairly while C. biafrae and C. montuosum are sparsely 

hairy. 

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TABLE 1: EPIDERMAL CELL CHARATERISTCIS OF THE CRASSOCEPHALUM SPECIES STUDIED 

Character Epidermal Anticlinal Epidermal Cell Length Epidermal Cell 

Cell Shape Cell Wall 

Width 

Species 

C. mannii 

Abaxial Surface 

Adaxial Surface 

C. biafrae 



C. crepidioides 



C. montuosum 



C. vitellinum 



C. rubens 



C. sarcobasis 



Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Irregular 

Sinuous 

Straight-arcuate 












37.70 ± 3.40 

36.99 ± 1.84 

39.81 ± 3.50 

59.67 ± 6.84 

41.49 ± 2.71 

55.53 ± 1.51 

49.07 ± 2.05 

48.40 ± 1.41 

32.04 ± 3.45 

56.97 ± 6.74 

39.54 ± 1.25 

56.05 ± 2.16 

37.15 ±1.41 

31.59 ± 3.47 

29.25 ± 1.22 

31.68 ± 5.06 

31.41 ± 1.20 

29.07 ± 2.05 

15.84 ± 0.93 

20.78 ± 6.90 

19.08 ± 0.69 

31.68 ± 5.07 

20.17 ± 0.70 

32.46 ± 3.51 

No. of 

Epidermal 

Cells 

1088 

1950 

2040 

960 

1570 

1576 

2784 

2570 

4334 

860 

Co.ef. 

of 

variability 

6.12 

8.27 

5.04 

11.17 

6.46 

7.25 

4.74 

8.92 

1.92 

6.58 

2.72 

7.07 

4.32 

7.10 

3.57 

3.20 

5.27 

8.07 

11.83 

6.71 

C. togoense 



Irregular 

Irregular 




31.54 ± 3.36 

36.05 ± 2.15 

27.49 ± 2.07 

17.82 ± 0.76 

31.05 ± 3.40 

15.16 ± 0.86 

2750 

1076 

4.82 

6.78 

6.65 

8.72 

32.64 ± 3.45 

19.45 ± 1.46 

2572 

5.15 

9.20 

777 

4.44 

8.26 

1080 

5.28 

7.07 

3.32 

6.15 

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TABLE 2: STOMATAL CHARATERISTCIS OF THE CRASSOCEPHALUM SPECIES STUDIED 

Character 

Stomatal 

µm 

Co.ef. Stomatal Index 

type 

Stomatal Width of var (%) 

Species 

C. mannii 



C. biafrae 



Anomocytic 

Contiguous 

None 

Contiguous 

Anomocytic 

Contiguous 

µm 

Stomatal 

Length 

24.64 ± 1.25 

- 

27.45 ± 0.40 

27.63 ± 1.36 

10.26 ± 0.54 

- 

24.82 ± 1.58 

13.77 ± 0.82 

1.32 

4.86 

- 

1.92 

3.95 

2.68 

- 

1.51 

1.45 

C. crepidioides 



Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

27.08 ± 1.20 

27.90 ± 1.29 

26.65 ± 1.29 

16.65 ±1.25 

4. 84 

4.50 

4.64 

7.50 

3.00 

1.87 

1.87 

C. montuosum 



C. vitellinum 



C. rubens 



C. sarcobasis 



C. togoense 



Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

Anomocytic 

Contiguous 

38.00 ± 1.90 

31.46 ± 1. 14 

31.86 ± 1.10 

27.63 ± 1.36 

27.16 ± 1.86 

25.72 ±1.68 

26.06 ±1.82 

20.65 ± 1.32 

29.13 ±1.20 

25.13 ± 1.76 

17.15 ± 1.31 

20.97 ± 1.50 

27.18 ± 4.39 

13.77 ± 0.82 

24.64 ± 1.47 

15.77 ± 0.76 

24.56 ±1.38 

14.64 ± 0.85 

27.63 ± 1.22 

17.86 ± 1.53 

4.24 

7.15 

3.45 

7.30 

3.45 

7.15 

4.92 

5.99 

2.86 

1.65 

5.92 

1.92 

5.86 

1.86 

4.92 

14.26 

9.07 

1.06 

1.15 

1.26 

3.37 

1.08 

2.68 

1.15 

3.70 

2.70 

Anomocytic 

Contiguous 

4.67 

7.88 

Anomocytic 

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Fig 1: Adaxial epidermis of C. mannii X 250 

Fig 2: Adaxial epidermis of Crassocephalum biafrae X 250 

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Fig 3: Adaxial epidermis of Crassocephalum crepidiodes X 250 

Fig 4: Adaxial epidermis of Crassocephalum montuosum X 260 

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Fig 5: Adaxial epidermis of Crassocephalum vitellinum X 150 

Fig 6: Adaxial epidermis of Crassocephalum rubens X 150 

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Fig 7: Adaxial epidermis of Crassocephalum sarcobasis X 150 

Fig 8: Adaxial epidermis of Crassocephalum togoense X 250 

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Fig 9: Abaxial epidemis of Crassocephalum biafrae X 250 

Fig 10: Abaxial epidermis of Crassocephalum crepidiodes X 150 

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Fig 11: Abaxial epidermis of Crassocephalum montuosum X 250 

Fig 12: Abaxial epidermis of Crassocephalum vitellinum X 150 

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Fig 13: Abaxial epidermis of Crassocephalum sarcobasis X 150 

Fig 14: Abaxial epidermis of Crassocephalum togoense X 150 

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Fig 15: Adaxial epidermis of C. mannii showing clusters of Trichomes at the mid vein. X 250 

4. DISCUSSION 

Hutchinson and Dalziel (1963) used only gross macro morphological features to classify different species in the 

genus Crassocephalum. However, results from the present studies shows that data from other lines of taxonomic 

evidence are needed for a more reliable, clear and comprehensive classification of the taxa. Thus information from 

micro morphology, have giving more detailed and modern data upon which a broad-based classification may be 

used. 

Stomatal characteristics such as the type, distribution, size and index are among the anatomical parameter used in 

plant taxonomy. The hypostomatic distribution of stomata in only C. mannii out of all the species studied is of 

taxonomic importance and could be used to delimit the taxon. The other species showed hypoamphistomatic 

distribution. The occurrence of contiguous stomata on abaxial surfaces of all the species studied shows that they are 

related despite their variation in other features. The anisocytic stomata on the adaxial surface of C. biafrae, C. 

vitellinum, C. sarcobasis could be used for delimitation of the taxa. Anomocytic stomata occurred on both surfaces 

of all the species except C. mannii. The sinuous anticlinal wall of the epidermal cells of adaxial surfaces of C. 

togoense and C. crepidioides is of diagnostic importance. Epidermal cell length among the species studies range 

from 31.54 ± 3.36 in C.sarcobasis to 49.07 + 2.05 in C. montuosum 

Trichomes (hairs) are epidermal features common to stems, leaves and other aerial organs; their high taxonomic 

value has long been appreciated.In all the species studied simple unbranched trichomes occurred but there exist 

variation in the distribution, density and length of the trichomes. Olowokudejo (1990) used trichome size and 

density to delimit West African genus Annona (Annonaceae) into 7 taxa. The high density of trichomes on the veins 

of the adaxial surface of C. mannii and its very low density on the other epidermal cells on the same adaxial surface 

is of taxonomic interest and could be used to delimit the taxon from the other species. C. vitellinum, C. crepidioides, 

C. sarcobasis and C. togoense which are densely hairy could also be delimited from C. biafrae and C. montuosum 

that are sparsely hairy. 

40



5. CONCLUSION 

Modern taxonomy leans very heavily on multiple characters rather than on single character, owning to the 

importance of epidermal characters, this study has made it clear that the presence of stomata on only the abaxial 

surface of C.mannii of diagnostic value. The occurrence of simple unbranched trichomes in the eight species studied 

viz C. biafrae, C. vitellinum, C. sarcobasis, C. crepidioides, C. montuosum, C. togoense, C. rubens and C. mannii 

showed that they are related. However the variation in the density, distribution and length of the trichomes could be 

used to delimit one taxon from each other. 

6. REFERENCES 

[1]. Bosch, C. H (2004). Crassocephalum rubens ( Juss .ex Jacq. ) S.Moore In Grubben.G.J.H & Dentor, O.A 

(Editors) PROTA 2: Vegetables / Legumes [CD- ROM] PROTA, Wageningen Nertherlands. 

[2]. Edeoga,H.O and Ikem C.I (2001). Comparative Morphology of leaf epidermis in three species of Boerhevia L 

J Econ Tax Bot 19:197-205 

[3]. Gill, L.S. (1988): Taxonomy of Flowering Plants. African Fep Publishers Ltd. Nig.p. 246 

[4]. Hutchinson, J. and Dalziel, M. (1963). Floral of West Tropical Africa. Crown agent, London Vol. 2:243 – 

246 

[5]. Mbagwu,F .N, Nwachukwu,C.U and Okoro,O.O Comparative Leaf Epidermal Studies on Solanum 

macrocarpon and Solanum nigrum. Research Journal of Bot. 3 (1): 45-48. 

[6]. Nwachukwu, C.U. and Edeoga H.O.(2006). Morphology of the leaf Epidermis in certain species of Indigofera 

L. (Leguminosae – Papilionoideae) Int. J.4: 40=43. 

[7]. Ogundipe, O.T. (1982). Leaf Epidermal studies in Genus Datura Linn (Solanaceae) Phytomorphology 42: 

209 – 217. 

[8]. Olorode, O. (1984). Taxonomy of West African Flowering Plants. University of Ife Press, Nigeria. Pp. 112- 

114. 

[9]. Olowokudejo, J.D (1990) Comparative Morphology of Leaf Epidermis in the Genus Annona (Annonaceae) in 

West Africa. Phytomorphology. 40:407 – 422. 

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