Topic
Aetoxylon
About: Aetoxylon is a research topic. Over the lifetime, 2 publications have been published within this topic receiving 27 citations.
Papers
TL;DR: The pollen of three closely related genera, Aetoxylon, Amyxa, and Gonystylus is compared in SEM and TEM with that of Thymelaeaceae, which has spherical, pantoporate grains with a crotonoid tectum in which the basic subunit is tnangular in shape and forms a continuous triangular array.
Abstract: The pollen of three closely related genera, Aetoxylon, Amyxa, and Gonystylus is compared in SEM and TEM with that of Thymelaeaceae, s. s. The Thymelaeaceae have spherical, pantoporate grains with a crotonoid tectum in which the basic subunit is tnangular in shape and forms a continuous triangular array. Thin section (TEM) and fractures (SEM) revealed that these subunits are attached to a ringlike network of horizontal rods. Within the Thymelaeaceae, the triangular subunits vary in the number of subdivisions and degree of fusion and form a morphological continuum. Aetoxylon, Amyxa, and Gonystylus also have spherical, pantoporate pollen but with a tectum in which almost all of the distinction of the subunits appears to have been lost. The structure of the exine in Aetoxylon, Amyxa, and Gonystylus, however, is unique thus far within the angiosperms. Thin section revealed a thick tectum with a layer of short or even granular columellae, then a thin, discontinuous layer from which larger columellae appear to hang. There is no evidence of an endexine even in the region of the apertures. The distinctive exine structure would support the treatment of Aetoxylon, Amyxa, and Gonystylus as a separate family, Gonystylaceae, allied to the Thymelaeaceae. AETOXYLON (Airy Shaw) Airy Shaw, and Amyxa Van Tiegh., each with a single species in Borneo, and Gonystylus with 25 species distributed through most of Malaysia, the Solomon Islands, and Fiji, have been treated as a separate family, Gonystylaceae, by Hutchinson (1959), or included in the Thymelaeaceae by Domke (1934), Wagenitz (1964), Airy Shaw (Willis, 1966), and Cronquist (1981), all of whom acknowledge the distinction of these three genera by segregating them as a subfamily, Gonystyloideae. Aetoxylon, Amyxa, and Gonystylus can be distinguished from the remaining Thymelaeaceae by a combination of characters: capsule fruit, numerous petals, elongate style, and pellucid-punctate leaves. These genera also lack the internal phloem that characterizes the vast t Received for publication 6 August 1984; revision accepted 5 February 1985. We thank J. L. Bittner, S. G. Braden, and W. Chissoe for their fine technical assistance. We are also grateful for the pollen samples sent by the late Dr. Jan Muller. This study was supported in part by a grant from Fluid Research from S. Dillon Ripley, and National Science Foundation Grants BSR-8002585 and BSR-8216349. majority ofthe Thymelaeaceae, as well as most of the order Myrtales. Archangelsky (1971 ), who described the pollen morphology of the Thymelaeaceae and allied families (1971), referred to their predominant crotonoid pattern as stellate. He considered the majority of the Thymelaeaceae to have typical stellate sculpturing, but described the Gonystylaceae as having cryptostellate sculpturing, and cited the "absolutely special type of their exines as a further criterion" for their treatment as an independent family. Of further interest, Archangelsky suggested that stellate sculpturing was one of the complex variables of simple reticulate sculpturing. As part of an extensive study of pollen morphology in the orders Myrtales (Patel, Skvarla and Raven, 1983, 1984) and Euphorbiales (sensu Cronquist, 1981; Nowicke, 1984; Nowicke and Skvarla, 1984), the pollen of more than 70 species representing 39 genera in the Thymelaeaceae have been examined. Aetoxylon sympetalum, Amyxa pluriconis, and four species of Gonystylus were included (see Table 1).
16 citations
1 Jan 2002
TL;DR: Agarwal et al. as discussed by the authors used field research in Papua New Guinea (PNG) to identify Gyrinops ledermannii Domke (Thymelaeaceae) as an agarwood-producing species for the first time.
Abstract: Field research conducted in Papua New Guinea (PNG) has recorded Gyrinops ledermannii Domke (Thymelaeaceae) as an agarwood-producing species for the first time. Aquilaria malaccensis Lam. (incl. A. agallocha Roxb.; Thymelaeaceae) or agarwood (also known as aloeswood, eaglewood, gaharu, and incensewood, and many other vernacular names) after infection by certain fungi develops a fragrant substance called agar in its wood. This has been traded since biblical times for its use in religious, medicinal, and aromatic preparations (see also Chadha, 1985). Agarwood-producing species in the Thymelaeaceae [Aetoxylon sympetalum (Steen. & Domke) Airy Shaw, Aquilaria beccariana Tiegh., A. filaria (Oken) Merr., A. hirta Ridl., A. malaccensis, A. microcarpa Baill., and Gonostylus bancanus (Miq.) Kurz] are found from India eastwards to Hainan, S China, and New Guinea. Agarwood is found naturally in only a small percentage of trees – with the highestgrade ‘product’ usually harvested from certain species of Aquilaria and despite the high levels of harvest and trade, only A. malaccensis is listed on Appendix II of the Convention on International Trade of Endangered Species of Wild Flora and Fauna (CITES). Over 1000 tonnes of agarwood were reported in international trade under the name A. malaccensis in 1998. The island of New Guinea is the eastern border of the agarwood-producing species’ range, and could also be the world’s last frontier for substantial wild agarwood stocks. But even New Guinea’s agarwood faces the threat of unprecedented levels of harvest and trade that have expanded over the past five years. On the PNG side of the border, harvesting has been prevalent since 1997 (O. Gideon, pers. comm. to TRAFFIC Oceania, 1999). At that time, PNG government authorities presumed that the species harvested for agarwood was A. filaria (Oken) Merr., which has been recorded from several locations in Irian Jaya (Ding Hou, 1960). The catalyst for this ‘sudden’ discovery of agarwood in PNG is most likely associated with Asian traders visiting the Sepik provinces bordering Irian Jaya, but could also involve Melanesian clan groups whose traditional lands traverse both sides of the border. Prior to the past five years, most indigenous PNGeans had never heard of the agarwood tree, nor used it for any traditional applications. It was widely regarded as just another forest tree unsuitable for making canoes or houses.
15 citations
Performance Metrics
| Year | Papers |
|---|---|
| 2002 | 1 |
| 1985 | 1 |