Phormium Tenax Research Articles

Biological flora of New Zealand 10. Phormium tenax, harakeke, New Zealand flax

We review the biosystematics, chemistry, phenology, ecology, and cultural and economic uses of Phormium tenax, a widespread iconic New Zealand monocotyledon. Phormium tenax is endemic to New Zealand, Norfolk Island, and the Chatham Islands, and is distinguished from the sole other member of the genus, P. cookianum, by its erect trigonous seed capsules and red flowers, despite incomplete barriers to hybridisation. Flowers produce abundant nectar and are bird pollinated. Seed is orthodox and tolerates drying, while chilling overcomes dormancy. Rich, well‐drained alluvial and organic soils encourage abundant growth in P. tenax but prolonged flooding and drought reduce growth and survival. Lack of tolerance to both frost and low mean annual temperatures distinguish its environmental niche from that of P. cookianum, but further research is required to characterise these differences more accurately. Phormium tenax is a significant component of vegetation on coastal cliffs, slopes, and dunelands; in estuarine shrublands; and lake margin and freshwater communities. Wide morphological variation in Phormium has led to cultivar development by Maori for weaving and by horticulturalists for ornamental garden use. Phormium tenax is important in many ecological communities as a food source, and is often used in restoration and revegetation plantings.

Improving Hygrothermal Performance in Epoxy-Biofibre Composites

Confocal microscopy and water diffusivity measurements were used to characterise the development of defects in biofibre-reinforced composite materials. Biofibres swelled more than the matrix when the specimen was immersed in water, but the associated distortion of the matrix rarely caused defects. The biofibres shrank faster than the matrix when the specimen was dried in air, causing debonding at the fibre-matrix interfaces and microcracks within the fibres. We started with coarse technical fibres from the leaves of harakeke (Phormium tenax), treated a portion with 1% NaOH, and pulped a portion at 170 °C. Water diffusivities for the corresponding composites increased over the first 3 wet-dry cycles, particularly for the composite made with untreated fibre, but were too small to be of concern for the composite made from pulped fibre.

Pulped Phormium tenax leaf fibres as reinforcement for epoxy composites

Abstract Leaf fibres from Phormium tenax (harakeke, New Zealand flax) were pulped at 170 °C with NaOH and anthraquinone. The pulp was wet laid to form mats, which were used to reinforce epoxy composites. The flexural modulus was almost as high as that measured for epoxy reinforced with glass chopped strand mat at the same weight fraction. The flexural strength was two-thirds that of the glass-reinforced composite. Failure was abrupt. SEM images showed torn fragments of fibre cell walls protruding from the fracture surface, indicating strong interfacial bonding. Good mechanical performance was attributed to the rarity of kink bands in the individual fibre cells, along with wrinkled cell-wall surfaces that enhanced the area of the fibre–matrix interface.

Epoxy composites reinforced with deacetylated Phormium tenax leaf fibres

Leaf fibres from Phormium tenax (harakeke, New Zealand flax) were treated with 1 wt.% aqueous NaOH at 30 °C to remove all of the acetyl groups, accounting for most of a 7% mass loss. Increasing the treatment time to 4 h showed no detectable increase in mass loss, but increasing the NaOH concentration to 5% doubled the mass loss by removing some of the xylans. Changes in fibre morphology were interpreted in terms of swelling of cell walls into lumens, followed by shrinkage on drying without reopening the lumens. Deacetylation retarded the rate of water uptake in unidirectional epoxy composites, but showed no detectable influence on the equilibrium moisture content, flexural modulus or strength. The results suggest that high levels of natural acetylation are not a useful feature of leaf fibres, at least in the context of reinforcement for epoxy composites.

Slimacomyces monosporus . [Descriptions of Fungi and Bacteria

Abstract Descriptions are given of Slimacomyces monosporus including its geographical distribution (Canada (British Columbia), Campbell Island, China (Sichuan), Japan, New Zealand, Cuba, Czech Republic, Germany, UK and Netherlands), hosts ( Araucaria sp., Juniperus communis, Juniperus sp., Phormium tenax, Picea sitchensis, Pinus contorta, P. mugo, P. nigra, P. resinosa, P. sosnowskyi, P. strobus, P. sylvestris, Pinus sp. and Rhododendron sp.), other associated organisms ( Anthostomella pedemontana, Cyclaneusma minus, Kriegeriella mirabilis, Pseudocercospora deightonii and Sympodiella acicola ), diagnostic features, biology and conservation status.

Harakeke reinforcement of soil–cement building materials: Manufacturability and properties

Fibre from the New Zealand flax plant, Phormium tenax, or Harakeke as it is otherwise known in Maori, has been used to reinforce soil–cement composites in an attempt to improve the strength and ductility of the composite material. Previous investigations have found the interfacial bond strength between the harakeke fibre and the soil–cement matrix to be an important factor for the strength of the composite. In an effort to improve the interfacial bond strength, an enamel paint coating has been applied to the fibre surface. Fibre lengths of 70 and 85 mm have been investigated along with fibre content levels of 0.6% and 0.8% measured as a percentage of the dry mass of the soil in the composite. Significant improvement in the ductility of the soil–cement composite has been realised with the addition of the harakeke fibre-reinforcement. It has been found that the specific make-up of the composite with regard to fibre length and content is not critical for the achievement of ductility improvement. Instead, these parameters were found to be controlled more by manufacturing issues such as the workability of the composite. It was found that 85 mm represented an upper limit on fibre length for the manual mixing technique adopted, while a maximum fibre content level of 0.8% was achieved. In order to reduce manufacturing difficulties, different mixing techniques were studied. A successful tumble mixing technique has been identified which is able to improve composite uniformity and the ease of manufacture. Based on the similarity of results for the two fibre content levels investigated, it is recommended that a level of 0.6% be adopted as this both improves the ease of manufacture and minimises the amount of fibre required. When the fibre content level was dropped below 0.6%, it was found that the material exhibited a more brittle failure behaviour.

Structural Differences among Fibers from Six Cultivars of Harakeke (Phormium tenax, New Zealand flax)

The microscopic structure of muka (fiber aggregate extracted from harakeke) (observed using light microscopy and scanning electron microscopy) from six selected cultivars of harakeke varied, and this may explain the differences perceived by weavers, and that different end uses are preferred for various cultivars. The dimensions of ultimate fibers ranged from 10.1 μm (Takaiapu) to 12.8 μm (Paretaniwha) in average-transverse-width and 3735 μm (Takirikau) to 4751 μm (Makaweroa) in length. The cultivars prized for muka (e.g. Arawa, Makaweroa) had the longest and finest ultimate fibers. The transverse-section shapes of fiber aggregate bundles varied among the cultivars. Tapamangu and Takaiapu had fiber bundles that were more uniformly shaped than the other cultivars studied, and Takirikau had a high yield of fiber aggregate bundles. Paretaniwha differed from the other five cultivars studied having an average number of narrow, non-uniformly shaped fiber aggregate bundles per unit width.

Competition‐dependent incompatibility in Phormium tenax: Does self‐fertilisation provide reproductive assurance?

New Zealand flax (Phormium tenax) has a reproductive system in which the early abscission of selfed flowers is determined by the degree of competition with crossed fruits on the same plant. It has been suggested that this functions as a form of reproductive assurance, allowing for high levels of outcrossing when pollinators are abundant, while ensuring seedset when pollinators are scarce. We performed experimental crosses and mating system estimation in natural populations to determine whether P. tenax can set seed in the absence of pollinators, and how pure and mixed pollen loads influence reproductive success and population‐level selfing rates. Phormium tenax can set seed autonomously, although if other flowers on the plant are available for outcrossing, resources are preferentially allocated to maturing those fruits. Experimental crosses suggest that flowers pollinated with mixtures of selfed and outcrossed pollen can result in fruitset, although fruitset is reduced if flowers pollinated with mixed pollen loads compete with cross‐pollinated flowers. Despite the potential for geitonogamy in P. tenax, outcrossing rates from five populations showed that these populations were universally outcrossing (t = 0.83–1.06). In P. tenax, self‐compatibility in the absence of competition from outcrossed pollen can provide some reproductive assurance, but in large populations, selfing and mixed mating rarely occur.

Structural studies of acidic xylans exuded from leaves of the monocotyledonous plants Phormium tenax and Phormium cookianum

The polysaccharides exuded from both Phormium tenax and Phormium cookianum leaves are acidic xylans with molecular weights in the range 1.3×10 6–1.7×10 6 Da. 1H and 13C NMR spectra show that in both cases the backbone comprises 1,4-linked β- d-Xyl p units and their substituted products, including a structural unit that is both 2- O-substituted and 3- O-acetylated. The sidechains contain α- d-GlcA and are terminated by β- d-Xyl p and α- l-Ara f units in relative proportions that differ between plant varieties. The polysaccharides are so highly branched that chain-terminating units account for approximately half of all structural units. These properties place the Phormium polysaccharides in a class which includes brea, sapote and yabo gums.

Post‐meiotic cytokinesis and pollen aperture pattern ontogeny: comparison of development in four species differing in aperture pattern

Pollen aperture patterns vary widely in angiosperms. An increasing number of studies indicate that aperture pattern ontogeny is correlated with the way in which cytokinesis that follows male meiosis is completed. The formation of the intersporal callose walls that isolate the microspores after meiosis was studied in four species with different aperture patterns (two monocots, Phormium tenax and Asphodelus albus, and two eudicots, Helleborus foetidus and Protea lepidocarpodendron). The way in which post-meiotic cytokinesis is performed differs between all four species, and variation in callose deposition appears to be linked to aperture pattern definition.

The controversial telomeres of lily plants

The molecular structure of the exceptional telomeres of six plant species belonging to the order Asparagales and two species of the order Liliales was analyzed using Southern blot and fluorescence in situ hybridization. Three different situations were found, namely: i) In the two Liliales species, Tulipa australis (Liliaceae) and Merendera montana (Colchicaceae), the chromosome ends display hybridization signals with oligonucleotides resembling telomere repeats of both plants (TTTAGGG)_nand vertebrates (TTAGGG)_n. ii) Asparagales species such as Phormium tenax (Hemerocallidaceae), Muscari comosum (Hyacinthaceae), Narcissus jonquilla (Amaryllidaceae) and Allium sativum (Alliaceae) lack both the plant telomere repeats and the vertebrate telomere repeats. iii) Two other Asparagales species, Aloe vera (Asphodelaceae) and an Iris hybrid (Iridaceae), display positive hybridization with the vertebrate telomere repeats but not with the plant telomere repeats. Southern blot hybridization revealed concurring results. On this basis, the composition of the telomere structure in this plant group is discussed.

Fibers from Three Cultivars of New Zealand Flax (Phormium tenax)

Botanists recognize only two kinds of New Zealand flax ( Phormium tenax and Phormium colensoi), while Māori weavers recognise over fifty different cultivars that have specific end-uses. Selected properties of muka4 (sclerenchyma fiber aggregates extracted from harakeke ( P. tenax)) from three of these cultivars (Arawa, Tapamangu, Makaweroa) are examined. Māori consider these three cultivars to provide excellent fibers that are easy to process. Tapamangu and Arawa are similar in terms of muka length, linear density, tenacity, extension at maximum load, and maximum extension, and the ultimate fibers of these cultivars have similar dimensions (width, length). Muka from Makaweroa is longer, not as tough, but with a linear density similar to the other cultivars. The ultimate fiber length of Makaweroa is greater, but the width is similar to Tapamangu and Arawa. Muka from the keel is longer, of higher linear density, and tougher (similar tenacity, higher maximum extension) compared to margin muka. The side of the leaf from which muka is extracted does not affect the properties measured.

Methods for characterizing plant fibers

The effectiveness of different microscopy techniques for measuring the dimensions of ultimate fibers from harakeke (Phormium tenax, New Zealand flax) was investigated using a factorial experimental design. Constant variables were geographical location, location of specimens along the leaf, season (winter), individual plant, a fourth leaf from a north-facing fan, age of plant, and cultivars (two). Experimental variables were microscopy techniques and measurement axis. Measurements of width and length of harakeke ultimate fibers depended on the microscopic preparation/technique used as well as the cultivar examined. The best methods were (i) transverse sections of leaf specimens 4 microm thick, embedded in Paraplast and observed using light microscopy, and (ii) nonfixed ultimate fibers observed using scanning electron microscopy.

Phormium tenax (Agavaceae) leaf anatomy effects on fibre extraction by the Maori haro method

Fracture mechanics tests and electron microscope studies showed that the fibre‐bundle sheath cells of Phormium tenax varieties from which fibre can be easily extracted by the Maori haro method were weak and thin‐walled. The method causes fracture to occur along this layer of cells that surround the fibre‐bundles. As a result, the fibre‐bundles that are removed from these varieties are very clean and require little further preparation before use.

Structural diversity of fructans from members of the order Asparagales in New Zealand

The water-soluble carbohydrates (WSCs) extracted from the underground parts of Arthropodium cirratum, Astelia banksii, Bulbinella hookeri, Dianella nigra and Xeronema callistemon, and the flower stem of Phormium tenax have been investigated. Extracts of A. cirratum, B. hookeri, D. nigra and P. tenax contained 108.4, 28.1, 41.9 and 29.7 mg gFW −1 WSCs, respectively. Thin-layer chromatography (TLC) showed that these species contained fructans. Extracts of A. banksii and X. callistemon each contained 11 mg gFW −1 WSCs or less, and TLC detected only monosaccharides and sucrose. Reverse-phase (RP) HPLC and glycosyl linkage analysis showed that extracts of B. hookeri contained predominantly a linear series of fructans, with 1-linked and terminal fructofuranosyl (Fru f) residues and terminal glucopyranose (Glc p). RP-HPLC of extracts of A. cirratum, D. nigra and P. tenax showed a more complex pattern of oligosaccharides. Linkage analysis showed that these extracts contained fructans with 1-linked Fru f, 6-linked Fru f and 1,6-branched Fru f. Extracts of D. nigra and P. tenax contained 6-Glc p with only trace amounts of terminal Glc p, while A. cirratum contained mostly terminal Glc p with a trace of 6-Glc p. Differences in fructan and fructo-oligosaccharide structure between species shown in this study, together with published data, suggests that there are differences in the activities of the various fructosyltransferases responsible for biosynthesis of fructans in species within the Asparagales.

Nectarivorous Feeding by Shiny Cowbirds: a Complex Feeding Innovation

Here I report a feeding innovation by Shiny Cowbirds (Molothrus bonariensis) in which the birds feed on the nectar of flax (Phormium tenax) flowers. Flax frequently is cultivated in Mar del Plata City, Buenos Aires Province, Argentina, as an ornamental plant, and the Shiny Cowbird is common there. The length of the cowbird's bill is similar to that of the flax flower tube, which permits the cowbird to access the nectar. Further, the panicle stem of the flax is sufficiently rigid for perching, and the short distance between the stem and the flower enables a perched cowbird to reach the flower. At this site, flax nectar probably is utilized in a sustainable manner, as the flowers apparently are not harmed. Future investigations should examine whether or not the observed behavior is restricted to this particular population and if it is not, determine the spatial and temporal extent to which it occurs.

Seed dormancy and germination of a panel of New Zealand plants suitable for re‐vegetation

Seeds of Carex trifida, Coprosma robusta, Cyperus ustulatus, Hebe stricta, Lepto‐spermum scoparium, Muehlenbeckia australis, Myrsine australis, Phormium tenax, P. tenax ’Yellow Wave’, and Sophora prostrata were assessed for germination and dormancy. Seeds of Carex trifida, Cyperus ustulatus, and Myrsine australis showed no germination in light or dark at 20°C, but a high percentage of seed of Carex and Cyperus germinated after 12 weeks of low stratification. Despite high viability, germination of Myrsine australis seeds was low and occurred only after 12 weeks of low temperature stratification. Germination was low for Muehlenbeckia australis in the light, at 20°C, but increased after 4 weeks of low temperature stratification. After 12 months, 50% of Coprosma robusta seeds germinated but germination was greater after 4 weeks or more of stratification. No seeds of Coprosma robusta or Muehlenbeckia australis germinated in the dark. Rapid germination of Hebe stricta seeds was obtained, with 100% of the seed germinating in the light but 7% in the dark. Leptospermum scoparium had rapid germination, with 100% germinating in the light but 3% in the dark. A low percentage of Phormium tenax seeds germinated in both the light and dark in the first month with no further germination, but after 8 weeks or more of low temperature stratification there was almost complete germination. There was rapid germination of Sophora prostrata seeds with 100% of the seed germinating in the light and dark.

Polynesian plant introductions in the Southwest Pacific: initial pollen evidence from Norfolk Island

Thick organic swamp sediments, buried under land fill on Kingston Common, preserves evidence of the Norfolk Island flora and vegetation back to the middle Holocene and probably much earlier times in the Late Quaternary. These sediments provide (1) a bench mark against which the impact of humans on the flora and vegetation of a long-isolated island can be assessed and (2) a means of determining whether particular plant genera and species are introduced or native to the island. Although sediments contemporary with Polynesian occupation about 800 years ago were destroyed by European draining and cultivation of the swamp during the early nineteenth century, the pollen data indicate that New Zealand flax (Phormium tenax) was introduced to Norfolk Island by Polynesians. Other putative exotics such as Ti (Cordyline), a bull-rush (Typha orientalis) and, less certain, herbs such as the sow thistle (Sonchus oleraceus), were part of the native flora long before the earliest recorded Polynesian settlement. Wildfires have been part of the landscape ecology of Norfolk Island since at least the middle Holocene.

Structure of fructans from excised leaves of New Zealand flax

The accumulation of total water-soluble carbohydrate, and specifically sucrose and fructan, by excised leaves of Phormium tenax and P. cookianum (family Phormiaceae J. G. Agardh, order Asparagales) was investigated. Total water-soluble carbohydrate content of excised leaves of P. tenax and P. cookianum increased during 48 h of continuous illumination at an average rate of 1.3 and 0.9 mg g −1 fresh weight leaf per hour, respectively. The sucrose content of excised leaves increased throughout the experimental period. The fructan content of excised leaves of P. tenax increased slightly throughout the experimental period, whilst that of P. cookianum was variable and showed no overall change. Chemical and spectroscopic analysis of the fructans obtained from the two Phormium species showed that they were similar to each other and contained mostly 1-linked and terminal fructofuranosyl (Fru f) residues, together with smaller amounts of 6-linked Fru f, 1,6-branched Fru f, terminal and 6-linked glucopyranosyl residues. Separation of the fructans by thin-layer and high-performance anion-exchange chromatography revealed the presence of a complex mixture of fructo-oligosaccharides and higher molecular weight fructan. The branched structure of the fructans isolated from excised leaves of Phormium resembles that of fructans and fructo-oligosaccharides isolated from some related species within the order Asparagales ( Agave vera cruz, Cordyline australis and Urginea maritima), but is distinct from the linear structure of fructans from others ( Allium cepa and Asparagus officinalis). The structural heterogeniety of fructans within both the order Asparagales and superorder Liliiflorae may be a useful chemotaxonomic aid.

Factors affecting the deterioration of the cellulosic fibres in black-dyed New Zealand flax (phormium tenax)

The fibre from New Zealand flax (Phormium tenax) is destabilized by a commonly used traditional black dye, which is an iron/plant polyphenol complex. By characterizing a variety of old and modern samples it has been shown that low pH and high iron content are responsible for the degradation. As degradation proceeds, the hue changes and the extent of degradation—as measured by water and 1% sodium hydroxide solubilities—increases. The fibre has a high proportion of the non-cellulosic xylan polysaccharide and this contributes to the high rate of degradation because it is susceptible to degradation and releases acetic acid. The rate of degradation in accelerated aging tests was increased by raising the relative humidity.