Australian Journal of Botany Australian Journal of Botany Society
Southern hemisphere botanical ecosystems

Effects of environmental conditions on the production of hypocotyl hairs in seedlings of Melaleuca ericifolia (swamp paperbark)

Randall W. Robinson A C , Paul I. Boon A , Nina Sawtell B , Elizabeth A. James B and Robert Cross B

A Institute for Sustainability and Innovation, Victoria University, St Albans Campus, PO Box 14428, MCMC, Vic. 8001, Australia.

B Royal Botanic Gardens Melbourne, Private Bag 2000, Birdwood Avenue, South Yarra, Vic. 3141, Australia.

C Corresponding author. Email:

Australian Journal of Botany 56(7) 564-573
Submitted: 1 September 2006  Accepted: 20 October 2008   Published: 26 November 2008


The production of hypocotyl hairs in the early stages of seedling development can strongly influence the success with which plants recruit sexually in harsh environments. Although wetlands are one type of environment in which seedlings might be expected to develop hypocotyl hairs, there have been few studies of these structures in the woody aquatic plants. We investigated the production of hypocotyl hairs in Melaleuca ericifolia Sm., a small wetland tree widely distributed across swampy coastal areas of south-eastern Australia, in relation to water availability, salinity, temperature and light regime. Hypocotyl hairs were ~20 mm long × 30 μm wide; in contrast, root hairs were generally less than 5 mm long and 15 μm wide. Hypocotyl hairs were produced only under a narrow range of environmental conditions—low salinity, low water availability, moderate temperature, and darkness—and seedlings that failed to produce hypocotyl hairs did not survive. Since the conditions under which hypocotyl hairs were produced were at least as, and possibly even more, restricted than those required for successful germination of seeds, it is likely that the successful sexual recruitment of M. ericifolia would be rare and episodic under conditions existing in most coastal wetlands in south-eastern Australia.


Aronne G de Micco V 2004 Hypocotyl features of Myrtus communis (Myrtaceae): a many-sided strategy for possible enhancement of seedling establishment in the Mediterranean environment. Botanical Journal of the Linnean Society 145 195 202 doi:10.1111/j.1095-8339.2003.00270.x

Baranov PA 1957 Coleorhiza in Myrtaceae. Phytomorph 7 237 243

Barrett-Lennard EG 2003 The interaction between waterlogging and salinity in higher plants: causes, consequences and implications. Plant and Soil 253 35 54

Bird ECF 1962 The swamp paper-bark. Victorian Naturalist 79 72 81

Bowkett LA Kirkpatrick JB 2003 Ecology and conservation of remnant Melaleuca ericifolia stands in the Tamar Valley, Tasmania. Australian Journal of Botany 51 405 413

Churchill AC 1983 Field studies on seed germination and seedling development in Zostera marina L. Aquatic Botany 16 21 29 doi:10.1016/0304-3770(83)90048-7

Corrick AH Norman FI 1980 Wetlands and waterbirds of the Snowy River and Gippsland Lakes catchment. Proceedings of the Royal Society of Victoria 91 1 15

Cowling SJ Lowe KW 1981 Studies of ibises in Victoria, I: records of breeding since 1955. Emu 81 33 39

Ducker SC , Brown VB , Calder DM (1977) An identification of the aquatic vegetation in the Gippsland Lakes. Report to the Ministry for Conservation, Victoria Environmental Studies Programme. Ministry for Conservation, Melbourne.

East LR 1935 Swamp reclamation in Victoria. Journal of the Institution of Engineers, Australia 7 77 91

Grierson C , Schiefelbein J (2002) Root hairs. In ‘The arabidopsis book’. (Eds C Somerville, E Meyerowitz) pp. 1–22. (The American Society of Plant Biologists: Rockville, MD)

Hofer R (1991) Root hairs. In ‘Plant roots: the hidden half’. (Eds Y Waisel, A Eshel, U Kafkafi) pp. 111–126. (Marcel Dekker: New York)

Jeanes JA (1996) Myrtaceae. In ‘Flora of Victoria. Vol. 3. Dicotyledons Winteraceae to Myrtaceae’. (Eds NG Walsh, TJ Entwistle) pp. 942–1044. (Inkata Press: Melbourne)

de Jong NH 2000 Woody plant restoration and natural regeneration in wet meadow at Comonderry Swamp on the south coast of New South Wales. Marine and Freshwater Research 51 81 89

de Jong TJ (1997) ‘Register of wetland restoration projects in Australia and New Zealand.’ Wetland Management Program. (Department of Environment and Natural Resources: Adelaide)

Kaul RB 1978 Morphology of germination and establishment of aquatic seedlings in Alismataceae and Hydrocharitaceae. Aquatic Botany 5 139 147 doi:10.1016/0304-3770(78)90057-8

Kozlowski TT 1997 Responses of woody plants to flooding and salinity. Tree Physiology Monographs 1 1 29

Kuo J 1993 Root anatomy and rhizosphere ultrastructure in tropical seagrasses. Australian Journal of Marine and Freshwater Research 44 75 84

Kuo J Kirkman H 1992 Fruits, seeds and germination in the seagrass Halophyloa ovalis (Hydrocharitaceae) Botanica Marina 35 197 204

Ladiges P Foord P Willis R 1981 Salinity and waterlogging tolerances of Melaleuca ericifolia. Australian Journal of Ecology 6 203 215

Matsuo M Shibayama H 2002 Morphological observation on development of juvenile seedlings of Monochoria vaginalis establishing on a flooded paddy soil surface. Weed Biology and Management 2 148 152 doi:10.1046/j.1445-6664.2002.00059.x

Môro FV Pinto ACR Dos Santos JM Damiao Filho CF 2001 A scanning electron microscopy study of the seed and post-seminal development in Angelonia salicariifolia Bonpl. (Scrophulariaceae). Annals of Botany 88 499 506 doi:10.1006/anbo.2001.1473

Morita O Ehara H Goto M Ikeda K Tsunekawa H 1995 Role of hypocotyl hairs in seedling establishment of wildflowers for landscaping. Grassland Science 41 71 73

Nishihiro J Sachiko A Nobuo F Washitani I 2004 Germination characteristics of lakeshore plants under an artificially stabilized water regime. Aquatic Botany 79 333 343

Parks Victoria (1997) ‘Lake Wellington wetlands draft management plan.’ (Parks Victoria: Melbourne)

Polya L 1961 Injury by soaking of Populus alba seeds. Nature 189 159 160 doi:10.1038/189159a0

Raulings EJ Boon PI Bailey PC Roache MC Morris K Robinson R 2007 Rehabilitation of swamp paperbark (Melaleuca ericifolia) wetlands in south-eastern Australia: effects of hydrology, microtopography, plant age and planting technique on the success of community-based revegetation trials. Wetlands Ecology and Management 15 175 188 doi:10.1007/s11273-006-9022-6

Roache MC Bailey PC Boon PI 2006 Effects of salinity on the decay of the freshwater macrophyte, Triglochin procera. Aquatic Botany 84 45 52 doi:10.1016/j.aquabot.2005.07.014

Robinson RR Boon PI Bailey PC 2006 Germination characteristics of Melaleuca ericifolia Sm. (swamp paperbark) and their implications for the rehabilitation of coastal wetlands. Marine and Freshwater Research 57 703 711 doi:10.1071/MF06006

Rutishauser R Novelo AR Philbrick T 1999 Developmental morphology of new world Podostemaceae: Marathrum and Vanroyenella. International Journal of Plant Sciences 160 29 43 doi:10.1086/314097

Salter J Morris K Bailey PCB Boon PI 2007 Interactive effects of salinity and water depth on the growth of seedling swamp paperbark (Melaleuca ericifolia Sm). Aquatic Botany 86 213 222 doi:10.1016/j.aquabot.2006.10.002

Young JA Martens E 1991 Importance of hypocotyl hairs in germination of Artemisia seeds. Journal of Range Management 44 438 442 doi:10.2307/4002740

Zar JH (2005) ‘Biostatistical analysis.’ (Prentice Hall: Englewood Cliffs, NJ)

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