New Materials of Eriocaulon L. from China

This paper consists of a part of pertinent data obtained through a critical study of Eriocaulaceae from China. Included in it are three new series: Leiantha, Robustiora and Mangshanensia; seven new species: Eriocaulon acutibracteatum, E. angustulum, E. bilobatum, E. leianthum, E. sclerophyllum, E. glabri-petalum and E. mangshanense; five new varieties: E. rockianum var. latifolium, E. merrillii var. longibracteatum, E. sikokianum var. Linanense, E. alpestre var. sichanense and E. nantoense var. micropetalum; two new combinations: E. yaoshanense var. brevicalyx; E. nantoense var. parviceps; three new records in China: E. brownianum, E.brownianum var.nilagirense, E. zollingerianum; five: E. henryanum, E.pullum, E. yaoshanense, E. taishanense and E.faberi. In addition, fifteen taxon names are newly reduced to synonyms: E. yunnanense=E. brownianum; E. longifolium, E. sexangulare var. longifolium, E. sinii, E. kwangtungense and E. willdinovianum = E. sexangulare; E. setaceum var. capillus-naiadis= E. setaceum; E. filifolium = E. yaoshanense; E. suishaense, E. merrillii var. suishaense=E.merrillii; E. kengii=E.sikokianum; E. whangii=E.buergerianum; E. nipponicum, E. decemflorum var. nipponicum= E. decemflorum and E. nantoense var.trisectum = E. nantoense var.parviceps.     

谷精草抑制α-葡萄糖苷酶活性成分研究

研究谷精草中α-葡萄糖苷酶活性抑制成分。采用色谱技术分离鉴定了26个化合物,对所有分离得到的化合物都进行了抗α-葡萄糖苷酶活性的体外筛选试验。其中化合物决明内酯-9-O-β-D-葡萄糖苷(3)、万寿菊素(7)、1,3,6,8-四羟基-2-甲氧基口山酮(13)、万寿菊素-3-O-β-D-吡喃葡萄糖苷(19)显示出显著的抑制活性,IC50分别为106.7、8.73、56.6、80.4μM。     

Shading by an invasive macrophyte has cascading effects on sediment chemistry

The submersed freshwater macrophyte Utricularia inflata is a recent invader of Adirondack Mountain lakes (NY, USA). Previous experiments suggested that U. inflata can indirectly change nutrient cycling in Adirondack lake ecosystems by reducing the growth of native isoetid macrophytes, which in turn affects sediment chemistry. A 13-week greenhouse experiment was conducted to test the hypothesis that shading can explain the detrimental effect of U. inflata on the native short-statured isoetid, Eriocaulon aquaticum. Eriocaulon aquaticum has a dense root system that oxidizes sediment by releasing oxygen; it also takes up carbon dioxide from sediment. Growth and asexual reproduction of E. aquaticum grown under shaded conditions was reduced significantly compared to an unshaded control (P < 0.001). Shading resulted in sediment changes: redox potential fell from 216 mV in the absence of shading to 76 mV under four layers of shade cloth (P < 0.0001). Shading also increased the concentration of extractable sediment ammonium (P < 0.01), as well as carbon dioxide concentrations (P < 0.0001) and pH of porewater (P < 0.05). The effect of U. inflata on the native isoetids and consequently on sediment chemistry closely matched the impact of shade cloth with similar light attenuation. Our results indicate that the principal mechanism by which U. inflata affects native isoetids and sediment chemistry is shading.     

Antibacterial phenolic components from Eriocaulon buergerianum

Five phenolic components, 1,3,6-trihydroxy-2,5,7-trimethoxyxanthone (1), 7,3′-dihydroxy-5,4′,5′-trimethoxyisoflavone (2), toralactone-9-O-β-d-glucopyranoside (3), patuletin-3-O-[2-O-E-feruloyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside] (4), patuletin-3-O-[β-d-glucopyranosyl-(1 → 3)-2-O-E-caffeoyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside] (5), along with 19 known compounds were isolated from Eriocaulon buergerianum (Eriocaulaceae). Their structures were determined by spectroscopic and chemical methods. All 24 isolated compounds were tested against the pathogenic bacteria Staphylococcus aureus (ATCC 25923); as a result, 10 compounds were found to exhibit antibacterial activity with MICs ranging from 32 to 256 μg/ml.     

<Emphasis Type="Italic">Eriocaulon epedunculatum</Emphasis>, a new species of <Emphasis Type="Italic">Eriocaulaceae</Emphasis> from the Western Ghats,India

Summary  A new species of Eriocaulon, E. epedunculatum (Eriocaulaceae) is described and illustrated from the Western Ghats, India.     

Floral development and vasculature in Eriocaulon (Eriocaulaceae) provide insights into the evolution of Poales

Background and AimsFloral developmental studies are crucial for understanding the evolution of floral structures and sexual systems in angiosperms. Within the monocot order Poales, both subfamilies of Eriocaulaceae have unisexual flowers bearing unusual nectaries. Few previous studies have investigated floral development in subfamily Eriocauloideae, which includes the large, diverse and widespread genus Eriocaulon. To understand floral variation and the evolution of the androecium, gynoecium and floral nectaries of Eriocaulaceae, we analysed floral development and vasculature in Eriocaulon and compared it with that of subfamily Paepalanthoideae and the related family Xyridaceae in a phylogenetic context.MethodsThirteen species of Eriocaulon were studied. Developmental analysis was carried out using scanning electron microscopy, and vasculature analysis was carried out using light microscopy. Fresh material was also analysed using scanning electron microscopy with a cryo function. Character evolution was reconstructed over well-resolved phylogenies.Key ResultsPerianth reductions can occur due to delayed development that can also result in loss of the vascular bundles of the median sepals. Nectariferous petal glands cease development and remain vestigial in some species. In staminate flowers, the inner stamens can emerge before the outer ones, and carpels are transformed into nectariferous carpellodes. In pistillate flowers, stamens are reduced to staminodes and the gynoecium has dorsal stigmas.ConclusionsFloral morphology is highly diverse in Eriocaulon, as a result of fusion, reduction or loss of perianth parts. The nectariferous carpellodes of staminate flowers originated first in the ancestor of Eriocaulaceae; petal glands and nectariferous branches of pistillate flowers originated independently in Eriocaulaceae through transfer of function. We present a hypothesis of floral evolution for the family, illustrating a shift from bisexuality to unisexuality and the evolution of nectaries in a complex monocot family, which can contribute to future studies on reproductive biology and floral evolution in other groups.     

An invasive macrophyte alters sediment chemistry due to suppression of a native isoetid

The submersed macrophyte Utricularia inflata (inflated bladderwort) is a recent invader of Adirondack Mountain lakes (NY, USA). A 15-week greenhouse experiment and a 7-week field experiment were conducted to test the hypothesis that this rootless species fundamentally changes sediment chemistry through its suppression of the native short-statured species, Eriocaulon aquaticum. E. aquaticum has an extensive root system that releases oxygen into the sediment. In greenhouse conditions, E. aquaticum raised the porewater redox potential of otherwise bare sediment from 25 to 324 mV, lowered the sediment porewater pH from 5.7 to 4.6, and depleted the dissolved inorganic carbon and ammonium concentrations in the sediment porewater by 68.4 and 96.0%, respectively (P<0.001 for all four parameters). A cover of U. inflata over E. aquaticum, however, greatly reduced the latter’s effect on redox potential (P<0.001), dissolved solutes (P<0.001), and pH (P<0.05). E. aquaticum biomass increased during the greenhouse experiment in the absence of U. inflata, but decreased in its presence (P<0.001). Redox and growth rate results from the field experiment paralleled those from the greenhouse experiment. Our data suggest that U. inflata may change nutrient cycling in Adirondack lake ecosystems by reducing the growth of native isoetid macrophytes, such as E. aquaticum, and consequently altering key features of sediment chemistry.     

Changes in the range of the medicinal herb Eriocaulon buergerianum Körnicke. (Eriocaulaceae) under climate change

• Eriocaulon buergerianum Körnicke. (Eriocaulaceae) is one of the most common and least expensive herbal medicines for eye disease. This species is facing potential threats from climate change. Insufficient biogeographic knowledge of this plant species can hinder its effective management for long‐term population survival.
• We integrated ecological niche modelling (Biomod2) with 70 records of E. buergerianum and eight environmental variables to estimate changes in distribution over time. A core area Zonation algorithm was introduced to identify conservation priority areas.
• Our results indicate that the range of E. buergerianum will likely decrease in the future: the overall range change on average is ?44.36 ± 21.56% (?3.70% to ?77.73%); values of range loss and range gain are 45.79 ± 20.30% (9.29–78.19%) and 1.43 ± 1.53% (0.18–5.59%), respectively. According to conservation priority analysis, the mandatory reserve (top 5%), negotiable reserve (0.95–0.9) and partial reserve (0.9–0.8) areas are 19,799, 19,799 and 39,597 km², respectively. The areas identified as conservation priority are located in the southeast, especially in northern Taiwan and the Wuyi Mountains.
• Based on these results, we suggest a re‐evaluation of the threatened status of this species, with a potential upgrade to the vulnerable (VU) category. To overcome the adverse conditions faced by populations of E. buergerianum in China, we propose a multi‐faceted conservation strategy involving more complete resource assessment, a monitoring system, medical research focused on revealing medicinal components or substitutes, and a regional development plan that considers both wildlife and socio‐economic issues.