SEM Studies of Achenes in Some Taxa of Asteraceae

VolumeInternational II Number Journal 2 2011 for [23-28] Environmen tal Rehabilitation and Conservation Volume IV No. 2 2013 [87 – 97] [ISSN 0975 - 6272] [ISSN 0975 - 6272]

SEM studies of Achenes in some taxa of Asteraceae

S. V. Kulkarni

Received: February 28, 2013 ⏐ Accepted: June 27, 2013 ⏐ Online: October 15, 2013

Abstract The present work studied the hispidum DC.; Synedrella vialis (Less.); micromorphological characters of achenes in triangular in Caesulia axillaries (Roxb.), seven taxa of the family Asteraceae from oblong in Amberboa ramosa (Roxb.), Nagpur (M.S.) namely Acanthospermum Spilanthes acmella Linn.; obovate in Conyza hispidum DC., Amberboa ramosa (Roxb.), aegyptiaca Ait. and oblong-obovate in Caesulia axillaries (Roxb.), Conyza Pulicaria angustifolia DC.; hilum basal and aegyptiaca Ait., Pulicaria angustifolia DC., lateral in Amberboa ramosa (Roxb.), basal and Spilanthes acmella Linn. and Synedrella vialis sublateral in Conyza aegyptiaca Ait. and basal (Less.). Dried, matured and healthy achenes in remaining taxa. Variations also observed in were collected, measured, described and surface of achenes of different taxa. Surface illustrated under light and scanning electron spiny in Acanthospermum hispidum DC.; awns microscopy (SEM). Results obtained from this in Caesulia axillaries (Roxb.), Synedrella investigation showed diversity in colour, vialis (Less.); phyllaries in Spilanthus acmella hilum, pappus, shape, size, spine, surface, and Linn. and hairy in remaining taxa. Ribs are ribs. Achenes are conical in Acanthospermum absent in all taxa except Amberboa ramosa (Roxb.). Micro and macro morphological Keywords: Achenes ⏐ SEM ⏐ micro - similarities in structure of achene showed

morphology ⏐ taxa ⏐ asteraceae interspecies relationships and reasons for them to be placed in the same family and differences in them showed to exist as distinct species. For correspondence: These characters have been used to strengthen

Department of Botany, Sevadal Mahila Mahavidyalaya, Nagpur the systematic position of the taxa. Email: [email protected]

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Introduction delimit the seven taxa of Asteraceae studied by Taxa of the family Asteraceae are herbs, author. These characters are used for the shrubs, rarely twiners or trees. The leaves are establishment of interspecies relationships simple, alternate or opposite, rarely compound. among the taxa investigated. The inflorescence is head or capitulum with Material and Methods involucre bracts. Marginal ray florets are Achene morphology of the seven taxa of ligulate and unisexual where as central disc Asteraceae was studied from Nagpur (M.S.). florets are tubular and bisexual. Anthers For morphological study fresh, mature, dried syngenesious and basifixed. Ovary inferior, and healthy achenes were collected from unilocular with one basal ovule. Fruit is of different localities of Nagpur and kept in vials. achene type or cypsela with persistent pappus For each taxon collector name and number is (Dutta, 1974). The family Asteraceae is an given (Appendix-I). When possible, upto four advanced position in systematic botany. It is specimens were analyzed to confirm the remarkable in many respects as it has number obtained results. Morphological characters of species worldwide in distribution and were examined under light and scanning effective mechanism of cross pollination. electron microscope. Light microscopy has These characters occur in majority of plants been carried out with the help of Leitz Ergaval but some variations have been recovered in microscope. For scanning electron microscopy large number of taxa. These variations led dry achenes were directly mounted on certain systematists to established division aluminum stubs, vaccum sputtered and within the family. Pollen carries the male scanned at 10-20 kv. The scanning was done gamete of seed plants. This character attracted on Quanta 200, Neitherland available at the attention of many scientists but scientists Automotive Research Association of India also used the seed (achene) morphology (ARAI), Pune (Maharashtra). The following (Nyananyo, 1987; Nyananyo and achene characters were studied: Olowokudejo, 1986) to produce more acceptable classification of the species in taxa Observations of Asteraceae. The achene characters of Acanthospermum Schranc. taxonomic value are shape, size, colour, Acanthospermum hispidum DC. surface, spine, pappus awns, phyllaries and hilum. Variations in these characters have been Achenes are 5x2mm, more or less conical, used in the delimitation of various taxa narrow at the base and broad at the apex, (Kynclova, 1970; Ritter & Miotlo, 2006; Abid golden brown in colour, two long spines at the and Zehra, 2007). apex, between these spines present four small curved spines, surface covered with spines and The present study is based on the hypothesis on lateral surface long curved spines are that achene characters played a vital role in the present which septate, hilum basal. delimitation of various taxa but has not been to

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SEM study reveals similar characters and few Amberboa (Pers.) Less. nom. cons. spines on lateral side, surface cellular, cells Amberboa ramosa (Roxb.) rectangular, small curved spines on the surface are directed upward, upper surface or curved Achenes are 5 – 6 x 2 mm, large, oblong, dark spines smooth where as rectangular reticulum brown in colour, narrow at both the ends and occur at base, small cavities present on the swollen in the middle, many vertical ribs, surface. (A, B, C) pappus many, longer than achene, unequal in length, light brown at the base and silvery creamy coloured at the apex, lateral hairs on the pappus scattered, small hairs on the lateral side, small cavities on the surface, hilum basal and lateral. SEM study reveals that achenes are ribbed, oblong, narrow at both the ends and swollen in the middle, hilum basal and lateral, constriction at the apex, surface rugose, cellular, cells rectangular, septa not clearly demarcated, each cell has reticulate network representing cavities, deposition on the surface, pappus at the apex, longer than achene, pappus of two types: (i) long and thin (ii) long and broad. Long and thin pappus have small pappus hairs having pulvinous base, alternate, apex acute while long and broad pappus have parallel lines showing ridges and grooves, pappus hairs opposite, acute having prominent ridge. (D, E and F).

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margin irregular, few patches on the surface (G, H & I)

Caesulia Roxb. Caesulia axillaries Roxb. Achenes are 2 x 1.25 mm, medium sized, thin, epapose, flattened, dark brown in colour, triangular in shape, narrow at the base and broad at the apex, thin flattened flap like outgrowth on the lateral side, two long and few short awns at apex, hilum basal. SEM study reveals that achenes are triangular, flattened, narrow at the base, broad and concave at the apex, hilum basal, surface cellular, cells rectangular, septa transverse, walls thin, reticulation occur in each cell, Conyza Less. nom. cons. curved, irregular, small, thin, triangular Conyza aegyptiaca Ait. outgrowth at the apex, from the lateral region of this septa secondary outgrowth developed, Achenes are 1.44 x 0.37 mm, small, flattened, thin, obovate, light brown in colour, surface

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covered with thin, long hairs in upward SEM study shows that achenes are thin, direction, vertical ribs on the surface, pappus obovate, base narrow, constricted, hilum basal white, thin, longer than achene, unequal in and sub lateral, apex concave, constriction length, lateral hairs on the pappus spirally occurs at the apex, surface cellular, cells thin arranged, reddish tinge at the apex of the hairs, rectangular with oblique septa, each cell thinly hilum basal and sub lateral. reticulated, hairs scattered on the surface are prominent, pair of hairs broad at the base, apex thin and acute, pappus thin, long, dark and light marking passing through the central region of the pappus, pappus hairs small, opposite, superposed, apex bright and obtuse. (J, K, L & M)

Pulicaria Gaertn. Pulicaria angustifolia DC.

Achenes are 2 x 0.96 mm, small, flattened, oblong-obovate, blackish brown in colour,

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truncate at apex, covered with hairs, pappus white, longer than seed, unequal in length pappus forming a laciniate cup, reddish tinge and hilum basal.

Spilanthus Jacq. Spilanthus acmella Linn.

SEM study reveals that seeds are long, straight, oblong-obovate, hilum basal, prominent, constriction occur at the base, pappus developed on fringed laciniate cup shaped structure, surface cellular, cells are small, hexagonal with thin oblique septa, walls thin and each cells have a brightly embedded and protruded structure; thin long unicellular hairs

scattered and embeded on the surface; pappus long, thin and hairy, pappus hairs lateral and Achenes are 2.5 x 1.3mm, medium size, parallel to the pappus. (N, O, P & Q) straight, oblong, black in colour, narrow at the base and broad at the apex, upward directed long brown hairs present on the lateral side,

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these hairs are swollen at the base, two Synedrella Gaertn., (nom. cons.) phyllaries of equal length present at the apex Synedrella vialis (Less). with notch and ridge in between the phyllaries, hilum basal.

SEM study reveals that achenes are oblong, flattened, straight, hilum basal but not prominent, ‘U’ shaped notch developed between two long phyllaries at the apex, margin hairy; surface rough, cellular, cells are large, rectangular; walls thin, deposition of substances occur on the surface, hairy setae like structure develop from the lateral margin which is broad at the base, bifurcated and pointed at the apex; vertical rib developed from base to apex. (R, S, T, U)

Achenes are 4 x 1.5mm, long, conical or triangular, dark brown or light brown in colour, tapering at the base and broad at the apex,

straight, spines like structure developed in

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upward direction on lateral side, two long awns study micro-morphological characters of present at the apex with small hairs on it, achene shows wide variations in seven surface hairy, hairs small, margin undulating, different taxa of Asteraceae (Table-1). Hence, hilum basal, not prominent. delimitation of taxa is difficult. Except SEM study reveals that seeds are long, conical Acanthospermum hispidum, Caesulia axillaries or triangular, tapering at the base and broad at and Synedrella vialis in remaining taxa achene the apex, straight, hilum basal, not prominent, shape is oblong, obovate and oblong-obovate surface hairy, hairs are small, apex bright and (Jayanarayanan and Manilal, 1998; Saklani et pointed, two long unequal awns at the apex, al., 2000; Abid and Qaiser. 2007, 2008; Abid surface cellular, cells small, hexagonal looks and Ali, 2010). Mature achenes are hairy in like honey comb, small, pointed, bright hairs Conyza aegyptiaca, Pulicaria angustifolia, protrude from the hexagonal cell surface, few Spilanthes acmella and Synedrella vialis cells show cavity like structure, awns consist except in Acanthospermum hispidum, of small rectangular cells, surface hairy, apex Amberboa ramosa, Caesulia axillaries. blunt. (V.W.X.Y). Achenes are ribbed in Amberboa ramosa and Conyza aegyptiaca as reported by Anderberg (1991). In Acanthospermum hispidum surface of achene is spiny which shows structural adaptation for effective dispersal by animals. Awns are present in Caesulia axillaries and Synedrella vialis where as phyllaries are present in Spilanthes acmella. These are dependable characters for identification of taxa (Jayanarayanan and Manilal, 1998). Achenes are epapose in Acanthospermum hispidum, Caesulia axillaries and Spilanthes acmella but Discussion and Conclusion pappus of unequal length and varying colour present in Amberboa ramosa, Conyza Most of the tribes of the family Asteraceae aegyptiaca, Pulicaria angustifolia (Table-1), have quite similar achene characters with the (Paria and Chinya, 1998; Abid and Qaiser, exception of Helianthae, Eupatorieae and 2007 , 2009; Abid and Zehera, 2007 and Inuleae (Abid and Qaiser, 2007, 2008, 2009). Swelankomo, et al, 2007). This is also a These characters are found taxonomically structural adaptation for effective dispersal by significant both at generic and species levels wind which plays important role in world wide which play an important role in demarcating distribution of taxa. Hilum basal in all taxa definite evolutionary level. These characters except in Conyza aegyptiaca and Amberboa have also been used to strengthen the ramosa (Singh and Pandey, 1981; Pandey et systematic position of the taxa. In the present al., 1983; Abid and Qaiser, 2007; Abid and

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Ali, 2010 and Shekher et al., 2011). In the Gaertn, (Inuleae-Asteraceae) from present work SEM characterization of achene Pakistan. Pak. J. Bot., 39(4): 991-997. surface also show variations in seven taxa of Abid, R. and Quaiser, M. (2008): Cypsela Asteraceae. Cell hexagonal with oblique septa Morphology of some genera in the tribe observed in Conyza aegyptiaca, honey comb Gnephalieae (Asteraceae) from like hexagonal cell in Synedrella vialis and Pakistan. Pak. J. Bot., 40(2): 473 – 485. rectangular type of cells in all other taxa of present work (Abid and Qaiser, 2008; Abid Abid, R. and Quaiser, M. (2009): Taxonomic and Ali, 2010). These characters have little significance of the cypsela Morphology influence upon the shaping of classification. in the tribe Anthemideae (Asteraceae) Micro and macro morphological similarities in from Pakistan and Kashmir. Pak. J. structure of achene showed interspecies Bot., 41(2): 555-579. relationships and reasons for them to be placed Abid, R. and Ali, N. (2010): Cypsela in the same family and differences in them morphology and its taxonomic showed to exist as distinct species. Different significance for the tribe Senecioneae morphological characters also show structural (Asteraceae) from Pakistan. Pak. J. adaptation for effective dispersal mechanism Bot. special issue, 42:117-133. by different agencies. All micro morphological Abid, R. and Zehra, N. (2007): Micro characters in the present work play an morphology of cypsela and its important role in demarcating definite taxonomic significance of some genera evolutionary level which has been used to in the tribe Inuleae from Pakistan. Pak. strengthen the systematic position of taxa. J. Bot. 39(5): 1407-1416. Acknowledgement Anderberg, A.A, (1991): Taxonomy and The author is thankful to Dr. B. Bhanot, phylogeny of the tribe Inuleae Director, Dr. A. R. Arankale, Sr. Assistant (Asteraceae). Pl. Syst. Evol., 176: 75- Director and Mr. D.r.Suryavanshi, Project 123. Engineer of The Automotive Research Dutta, A.C. (1974): Botany for Degree Association of India (ARAI), Pune for their Students. Calcutta, Oxford University permission and best cooperation during Press. Delhi, Bombay, Madras. scanning of research material. Thanks are to Dr. P.N.Charde, Principal, Sevadal Mahila Jayanarayanan, T. and Manilal, K. (1998): Mahavidyalaya, Nagpur for his cooperation Achene morphology of Compositae and its and inspiration during work. taxonomic significance. Rheeda Eight I.A.A.T. Annual Conference and National REFERENCE Seminar on “Biodiversity Conservation and Abid, R. and Quaiser, M. (2007): Cypsela Taxonomy of Tropical Flowering Plants.” pp. Morphology of the genus Pulicaria 10.

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Table 1: Achene characters in some taxa of Asteraceae

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Kynclova, M. (1970): Comparative Ritter, M.R. and Miotlo, S.T. (2006): morphology of achenes of the tribe Micromorphology of fruit surfaces in Anthemidae Cass. (Asteraceae) and its species of Mikania Willd. (Asteraceae) taxonomic significance. Preslia occurring in Rio Grande do sul state, (Praha), 42: 33-53. Brazi. Acta Bot. Bras., 20(1): 241-247. Nyananyo, B. L. (1987): Seed coat Saklani, A.; Rao, R.R. and Chaudhary, L.B. morphology in Calandrinia (2000): SEM characterization of (Portulacaceae) and its taxonomic achene morphology towards the significance. J. Plant. Sci., 3: 93-97. taxonomy of Indian species of Nyananyo, B. L. and Olowokudejo, J. D. Saussurea DC. (Asteraceae). Rheedea, (1986): Taxonomic studies in the genus 10 (01): 1-18. Talinum (Portulacaceae) in Nigeria. Shekhar, S.; Pandey, A. K. and Anderberg, Willdenowia Berlin. 15: 455-463. A.A. (2011): Cypsela morphology and Pandey, A.K.; Chopra, S. and Singh, R.P. anatomy in some genera formerly (1983). Development and structure of placed in Inula (Asteraceae: Inuleae- seeds amd fruits in Compositae, tribe Inulinae). Rheedea, 21(1): 13-22. Inuleae. Proc. Indian Acad. Sci. (Pl. Singh, R. P. and Pandey, A. K. (1981): Sci.), 92(6): 467-471. Structure of seed and fruits in Paria, N. and Chinya, S. B. (1998): Flora Compositae: Tribe- Asteraeae. J. I. B. micro morphology of some Indian S., 60, VII-21: 60. Asteraeae and its implication in Swelankomo, N.; Mucina, L. and Herman, taxonomy. Rheeda Eight I.A.A.T. P.P.J. (2007): Phenetic classification of Annual Conference and National cypselas in Ursinia (Anthemidae, Seminar on “Biodiversity Conservation Asteraceae). S. Afr. J. Bot., 73(2): 316. and Taxonomy of Tropical Flowering

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