Diversity of Acanthaceae in Phu Wua Forest, Bueng Kan Province

บทคัดย่อ การสำรวจพืชวงศ์เหงือกปลาหมอ บริเวณเส้นทางศึกษาธรรมชาติในป่าภูวัว จังหวัดบึงกาฬ ตั้งแต่เดือนพฤศจิกายน พ.ศ. 2559 ถึงเดือนพฤษภาคม พ.ศ. 2561 โดยบันทึกข้อมูลนิเวศวิทยา ระยะเวลาออกดอกและติดผล จัดทำตัวอย่างพรรณไม้แห้งเพื่อเป็นตัวอย่างอ้างอิง และสร้างรูปวิธานระบุชนิด พบพืชวงศ์นี้ จำนวน 26 ชนิด 17 สกุล สกุลที่พบมากที่สุดคือ Justicia L. และ Strobilanthes Blume พบ 4 ชนิด รองลงมาคือ สกุล Andrographis Wall. ex Nees, Phlogacanthus Nees และ Ruellia L. พบ 2 ชนิด ส่วนสกุลที่พบเพียงหนึ่งชนิด ได้แก่ Asystasia Blume, Barleria L., Chroesthes Benoist, Dyschoriste Ness in Wall., Hemigraphis Nees, Hygrophila R.Br., Lepidagathis Willd., Nelsonia R.Br., Peristrophe Nees, Phaulopsis Willd., Rungia Nees และ Staurogyne Wall. ในจำนวนนี้ไม่สามารถระบุชื่อวิทยาศาสตร์ได้ 2 ชนิด ได้แก่ Dyschoriste sp. และ Strobilanthes sp. คำสำคัญ: อนุกรมวิธานพืช, การอนุรักษ์, บึงกาฬ ABSTRACT Acanthaceae species were surveyed along the nature trails in Phu Wua forest, Bueng Kan province from November 2016 to May 2018. Ecological and phonological data, as well as Voucher specimens, were provided. A key to species was constructed. There are 26 species and 17 genera, the most common genera were Justicia L. and Strobilanthes Blume with four species each. Andrographis Wall. ex Nees, Phlogacanthus Nees and Ruellia L. were the second most common genera with two species each. Asystasia Blume, Barleria L., Chroesthes Benoist, Dyschoriste Ness in Wall., Hemigraphis Nees, Hygrophila R.Br., Lepidagathis Willd., Nelsonia R.Br., Peristrophe Nees, Phaulopsis Willd., Rungia Nees and Staurogyne Wall. were found in one species each. Among these, two species Dyschoriste sp. and Strobilanthes sp. could not be identified.Keywords: Plant taxonomy, Conservation, Bueng Kan

Two mycoheterotrophic orchids from Thailand tropical dipterocarpacean forests associate with a broad diversity of ectomycorrhizal fungi

<p>Abstract</p> <p>Background</p> <p>Mycoheterotrophic plants are considered to associate very specifically with fungi. Mycoheterotrophic orchids are mostly associated with ectomycorrhizal fungi in temperate regions, or with saprobes or parasites in tropical regions. Although most mycoheterotrophic orchids occur in the tropics, few studies have been devoted to them, and the main conclusions about their specificity have hitherto been drawn from their association with ectomycorrhizal fungi in temperate regions.</p> <p>Results</p> <p>We investigated three Asiatic Neottieae species from ectomycorrhizal forests in Thailand. We found that all were associated with ectomycorrhizal fungi, such as Thelephoraceae, Russulaceae and Sebacinales. Based on ¹³C enrichment of their biomass, they probably received their organic carbon from these fungi, as do mycoheterotrophic Neottieae from temperate regions. Moreover, ¹³C enrichment suggested that some nearby green orchids received part of their carbon from fungi too. Nevertheless, two of the three orchids presented a unique feature for mycoheterotrophic plants: they were not specifically associated with a narrow clade of fungi. Some orchid individuals were even associated with up to nine different fungi.</p> <p>Conclusion</p> <p>Our results demonstrate that some green and mycoheterotrophic orchids in tropical regions can receive carbon from ectomycorrhizal fungi, and thus from trees. Our results reveal the absence of specificity in two mycoheterotrophic orchid-fungus associations in tropical regions, in contrast to most previous studies of mycoheterotrophic plants, which have been mainly focused on temperate orchids.</p

The Pomatocalpa maculosum Complex (Orchidaceae) Resolved by Multivariate Morphometric Analysis

Principal components analysis (PCA) was employed to analyse the morphological variation among 63 herbarium specimens tentatively identified as Pomatocalpa andamanicum (Hook.f.) J. J. Sm., P. koordersii (Rolfe) J. J. Sm., P. latifolium (Lindl.) J. J. Sm., P. linearifolium Seidenf., P. maculosum (Lindl.) J. J. Sm., P. marsupiale (Kraenzl.) J. J. Sm., P. naevatum J. J. Sm., or P. siamense (Rolfe ex Downie) Summerh. Thirty-seven quantitative and 5 binary characters were included in the analyses. Taxa were delimited according to the observed clustering of specimens in the PCA plots, diagnostic characters were identified, and the correct nomenclature was established through examination of type material. Four species could be recognized viz, P. diffusum Breda (syn. P. latifolium), P. fuscum (Lindl.) J. J. Sm. (syn. P. latifolium), P. marsupiale (syn. P. koordersii) and P. maculosum. For the latter species, two subspecies could be recognized, viz P. maculosum (Lindl.) J. J. Sm. subsp. maculosum (syn. P. maculosum, P. naevatum p.p.) and P. maculosum (Lindl.) J. J. Sm. subsp. andamanicum (Hook.f.) S. Watthana (syn. P. andamanicum, P. linearifolium, P. siamense, P. naevatum p.p.). An identification key and a taxonomic synopsis are provided