“Hairy” bark in Lannea schweinfurthii (Anacardiaceae): hyperhydric-like tissue formed under arid conditions

in IAWA Journal
Restricted Access
Get Access to Full Text
Rent on DeepDyve

Have an Access Token?

Enter your access token to activate and access content online.

Please login and go to your personal user account to enter your access token.


Have Institutional Access?

Access content through your institution. Any other coaching guidance?



A remarkable, almost fur-like “indumentum” of velvety “hairs” (sometimes referred to as “fungi”) occurs on the roots (and to a lesser extent also on the trunk) of Lannea schweinfurthii var. stuhlmannii and is known as vhulivhadza in the Venda language (Tshivenḓa). The hairs are traditionally used by the Venda people (Vhavenḓa) of the Limpopo Province of South Africa, for various biocultural purposes. A detailed anatomical study of the origin, structure and development of these unusual “hairs” showed that they are of peridermal origin and develop from dense clusters of phelloid cells which are scattered within the stratified phellem. These cells are capable of considerable radial elongation thus forming hair-like radial files of elongated phelloid cells. The “hairy” patches on the bark may also develop from lenticels which become hypertrophied. These clusters of phelloid cells resemble the hyperhydric tissue which is reportedly formed in periderm of stems exposed to a water-saturated environment in some plant species. The formation of hyperhydric-like tissue in roots and stems of L. schweinfurthii var. stuhlmannii occurs, however, under relatively arid conditions. Since this tissue contains large intercellular spaces, it may also be regarded as a specialized type of aerenchymatous phellem. The adaptive significance, if any, of the phelloid “hairs” remains unknown.

“Hairy” bark in Lannea schweinfurthii (Anacardiaceae): hyperhydric-like tissue formed under arid conditions

in IAWA Journal



Angeles G. 1990. Hyperhydric tissue formation in flooded Populus tremuloides seedlings. IAWA Bull. n.s. 11: 8596.

Angeles G. 1992. The periderm of flooded and non-flooded Ludwigia octovalvis (Onagraceae). IAWA Bull. n.s. 13: 195200.

Angeles G Evert RF Kozlowski TT . 1986. Development of lenticels and adventitious roots in flooded Ulmus americana seedlings. Can. J. For. Res. 16: 585590.

Angyalossy V Pace MR Evert RF Marcati CR Oskolski AA Terrazas T Kotina E Lens F Mazzoni-Viveiros SC Angeles G Machado SR Crivellaro A Rao KS Junikka L Nikolaeva N Baas P . 2016. List of microscopic bark features. IAWA J. 37: 517615.

Brundrett MC Enstone DE Peterson CA . 1988. A berberine-aniline blue fluorescent staining procedure for suberin, lignin, and callose in plant tissue. Protoplasma 146: 133142.

Coates Palgrave M. 2002. Keith Coates Palgrave Trees of southern Africa Ed. 3. Random House StruikCape Town.

Donaldson LA Radotic K . 2013. Fluorescence lifetime imaging of lignin autofluorescence in normal and compression wood. J. Microsc. (Oxford U.K.) 251: 178187.

Echlin P. 2009. Handbook of sample preparation for scanning electron microscopy and X-ray microanalysis. SpringerNew York.

Feder N O’Brien TP. 1968. Plant microtechnique: some principles and new methods. Amer. J. Bot. 55: 123142.

Gardner RO . 1975. Vanillin-hydrochloric acid as a histochemical test for tannin. Stain Technol. 50: 315317.

Grace OM Prendergast HDV Jäger AK Van Staden J . 2003. Bark medicines used in traditional healthcare in KwaZulu-Natal, South Africa: An inventory. S. Afr. J. Bot. 69: 301363.

Hook DD Scholtens JR . 1978. Adaptations and flood tolerance of tree species. In: Hook DD Crawford RMM (eds.) Plant life in anaerobic environments: 299–331. Ann Arbor Science PublishersAnn Arbor.

Hutchings A Scott AH Lewis G Cunningham A . 1996 . Zulu medicinal plants . University of Natal PressPietermaritzburg.

Jansen PCM Cardon D . 2005. Plant resources of tropical Africa 3. Dyes and Tannins: pp. 101105.

Jensen WA . 1962. Botanical histochemistry. Freeman & Co.San Francisco.

Johansen DA . 1940. Plant microtechnique. McGraw-HillNew York.

Kawase M. 1981. Anatomical and morphological adaptations of plants to waterlogging. Hort-Science 16: 3034.

Kokwaro JO . 1986. Anacardiaceae. Flora of Tropical East Africa. Anacardiaceae: pp. 1026.

Kokwaro JO Gillett JB . 1980. Notes on the Anacardiaceae of Eastern Africa. Kew Bull. 34: 748753.

Kozlowski TT . 1984. Responses of woody plants to flooding. In: Kozlowski TT (ed.) Flooding and plant growth: 129–163. Academic PressNew York.

Kuo-Huang LL Hung LF . 1995. The formation of lenticels on the branches of Ficus microcarpa L.f. Taiwania 40: 139150.

Küster E. 1925. Pathologische Pflanzenanatomie Ed. 3. Gustav FischerJena.

Liengme CA . 1981. Plants used by the Tsonga people of Gazankulu. Bothalia 13: 501518.

Mabogo DEN . 1990. The ethnobotany of the Vhavenda. MSc. thesis University of Pretoria.

Ramovha LI . 1997. The taxonomic significance of bark structure in southern African Anacardiaceae. MSc. thesis University of Pretoria.

Roth I. 1981. Structural patterns of tropical barks. Encyclopedia of plant anatomy. Gebrüder BorntraegerBerlin.

Stevens KJ Peterson RL Reader RJ . 2002. The aerenchymatous phellem of Lythrum salicaria (L.): a pathway for gas transport and its role in flood tolerance. Ann. Bot. (Oxford U.K.) 89: 621625.

Teakle N Armstrong J Barrett-Lennard EG Colmer TD . 2011. Aerenchymatous phellem in hypocotyl and roots enables O2 transport in Melilotus siculus . New Phytol. 190: 340350.

Thiers B. [continuously updated]. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. http://sweetgum.nybg.org/science/ih/

Thomas R Fang X Ranathunge K Anderson TR Peterson CA Bernards MA . 2007. Soybean root suberin: anatomical distribution, chemical composition, and relationship to partial resistance to Phytophthora sojae . Plant Physiol. 144: 299311.

Topa MA McLeod KW . 1986. Aerenchyma and lenticel formation in pine seedlings: a possible avoidance mechanism to anaerobic growth conditions. Physiol. Plant. 68: 540550.

Van Wyk B Van Wyk P Van Wyk B-E . 2008. Photo guide to trees of southern Africa Ed. 2. Briza PublicationsPretoria.

Van Wyk B Van Wyk P . 2013. Field guide to trees of southern Africa Ed. 2. Struik NatureCape Town.

Verboven P Pedersen O Herremans E Ho QT Nicolaï BM Colmer TD Teakle NL . 2012. Root aeration via aerenchymatous phellem: three-dimensional micro-imaging and radial O2 profiles in Melilotus siculus . New Phytol. 193: 420431.


  • View in gallery

    Root “hairs” of Lannea schweinfurthii var. stuhlmannii. – A: Matchbox with the “hairs” sold by the Vhavenḓa people in the traditional market in the Limpopo province, South Africa. – B & C: Exposed root with “hairy” patches on the lower part. Golden brown “hairy” patches below the soil surface are indicated by arrows. – D: “Hairs” collected from the root bark.

  • View in gallery

    Bark on the trunk of Lannea schweinfurthii var. stuhlmannii. – A: The tree near Shakadza village from which the bark was examined in the present study. – B: Portion of the trunk exposed to regular moisture resulting from runoff after rain. – C–E: Patch of “hairs” (h) with flat solid remnants of phellem (p) and lenticels (L) on the bark surface shown at different magnifications.

  • View in gallery

    Transverse sections of bark of Lannea schweinfurthii var. stuhlmannii. – A: Cortex and epidermis with multicellular dendritic trichome from young stem; subepidermal initiation of phellogen (arrow). – B: Freehand section of root periderm under fluorescence microscope showing stratified phellem with lignified U-shaped cells (white arrows). – C: Mature bark from trunk showing secondary phloem (sp) with phloem rays (r) and multilayered phelloderm (pd) with prismatic crystals (asterisks) and clusters of sclereids (s).

  • View in gallery

    Transverse sections (freezing microtome) of the trunk bark of Lannea schweinfurthii var. stuhlmannii showing the formation of “hairy” patches in periderm. – A–F: Unstained sections. – A: Bark with secondary phloem (sp), phelloderm (pd) and phellem (p) with a cluster of phelloid cells (ph) in early stage of its formation. – B: Periderm with phelloderm (pd) containing prismatic crystals (white arrows) and phellem (p) with a cluster of elongated phelloid cells (ph) in early stage development. – C & D: “Hairy” patch in a slightly later stage of development. The relationship between ordinary phellem cells (p) and phelloid cells (ph) is evident. – E & F: Strands of elongated phelloid cells forming multicellular “hairs” with a somewhat jointed appearance. – G & H: Stained sections. “Hairy” patch in late stage of development under different magnifications. – G: The series of cells forming the hairs are numbered.

  • View in gallery

    Transverse sections (ultramicrotome) of the root periderm of Lannea schweinfurthii var. stuhlmannii showing the formation of “hairy” patches. – A & B: Early stage in formation of the phelloid cell clusters (ph) in phellem; phellem cells with lignified U-shaped walls (U) and phelloderm (pd) are also visible. – C: Cluster with somewhat radially expanded phelloid cells (ph). – D–F: Clusters with strands of considerably elongated phelloid cells (ph). – F: Phelloid cells between layers of ordinary phellem cells (p).

  • View in gallery

    Transverse sections of the root periderm (hand sections) under scanning electron microscope of Lannea schweinfurthii var. stuhlmannii. – A & B: Well-developed phelloid “hairs” (ph), ordinary phellem (p) and phelloderm (pd). – C: Multicellular phelloid “hairs” with a somewhat jointed appearance.

Index Card

Content Metrics

Content Metrics

All Time Past Year Past 30 Days
Abstract Views 11 11 5
Full Text Views 8 8 8
PDF Downloads 3 3 3
EPUB Downloads 1 1 1