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Type materials of Cremanthodium acernuum, C. smithianum and Cathcartia smithiana. A. Cremanthodium acernuum:
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Cremanthodium acernuum has been previously placed in synonymy with C. smithianum. However, our examination of herbarium specimens and field expedition have shown that it is quite distinct from C. smithianum by its heads erect, ray florets white, leaf margins variously incised with acute teeth. Cathcartia smithiana, which is listed as the basionym o...
Citations
... While working on the floristic diversity of Eastern Himalayan state Arunachal Pradesh, India (Borah et al. 2019;2020a, b, c, d, e, f), an unidentifiable and remarkable species of Cremanthodium was collected and photographed from alpine region of Tawang District at 4100 m altitude in August 2017. Detailed study of Cremanthodium species of India and adjoining countries, including protologues, type specimens, other herbarium specimens and relevant taxonomic literature (Good 1929;Hajra et al. 1995;Liu and Illarionova 2011;Wang et al. 2015;2016a, b, c, d, e, f;2017a, b;2018a, b;2019;Chen and Xu 2016;Fei et al. 2019) proved this to be a new species hitherto unknown to science, which is described here as a novelty. This new species was collected again from the same locality in September 2020. ...
Cremanthodium indicum D.Borah, R.Kr. Singh & Thungon (Asteraceae, Senecioneae), a new species from Eastern Himalayan state Arunachal Pradesh, India is described and illustrated. The new species is allied to Cremanthodium nobile (Franch.) Diels ex H.Lév. in having elliptic-obovate basal leaves, solitary, nodding capitula and hemispheric involucre, but differs by densely pale yellow tomentose stem, stem leaves 5-9, 1.6-2.1 cm distant, outer phyllaries 2.3-2.8 mm wide, inner phyllaries elliptic, 3-5 mm wide, apex acute, ray lamina creamy, oblong, 2-2.3 cm long, apex truncate, distinctly 3-dentate, ray tube 1.5-2 mm long, tubular florets creamy, 8-9 mm long and pappus 6-8 mm long.
... Recently, 69 species have been recognized (Liu & Illarionova 2011). Subsequently, many new contributions have been made to this genus, including the descriptions of five new species (Wang et al. 2015(Wang et al. , 2016a(Wang et al. , b, 2018, the reinstatements of two names (Chen & Xu 2016, Wang et al. 2016c, and the reductions of four names to synonymy (Wang et al. 2016(Wang et al. , 2017a. In total, 72 species are recognized currently. ...
... 2−5 mm) wide. With the addition of Cremanthodium magnificum, 9 species are currently recognized in Myanmar (Kress et al. 2003, Liu & Illarionova 2011, Chen & Xu 2016, Wang et al. 2017a). Among them, C. magnificum can be readily distinguished by the pinnate leaf veins, large-sized leaves and paniculate-racemose synflorescence. ...
Cremanthodium magnificum (Asteraceae-Senecioneae), a new species from northern Myanmar, is described and illustrated. It is somewhat similar to both C. chungdienense and C. pyrolifolium in having robust stature, large-sized leaves and hemispheric involucre. However, C. magnificum differs from C. chungdienense mainly by stem indumentum, leaf shape, capitulum number and synflorescence type. From C. pyrolifolium, C. magnificum is distinct by stem indumentum, leaf shape, capitulum number and ray lamina shape.
... Cremanthodium atrocapitatum was described by Good (1929) on the basis of a single collection, Farrer 1877 (E; Fig. 1), from the Chawchi pass in Gongshan, northwestern Yunnan, China (not in northeastern Myanmar as stated in the protologue; see Chen & Xu (2016) for the localization of the Chawchi pass). He contrasted the species with C. microcephalum Handel-Mazzetti (1920: 174) (= Ligularia microcephala as generally recognized; Figs. 2, 3), very probably due to their resemblance in the absence of the ray florets, the colour of the capitula, and the leaf shape. ...
Cremanthodium atrocapitatum (Asteraceae, Senecioneae) has been previously largely misunderstood, resulting in considerable taxonomic confusion involving several taxa. Based on observations of both herbarium specimens (including type material) and living plants, here we clarify the taxonomic identity of this species. The Xizang (Tibet) plants previously referred to C. atrocapitatum are described as a new species, i.e. C. bomiense. Cremanthodium campanulatum var. brachytrichum is found to be very close to C. atrocapitatum rather than C. campanulatum, and is thus treated as C. atrocapitatum var. brachytrichum.
... Cuneata Y. Ling ex S.W. Liu (1982: 52) under the same section. From the other seven species currently referred to this series (Chen 2010, Chen & Xu 2016, C. principis is readily distinguished by the leaf shape and the tomentum on the underside of the leaves. ...
Examination of herbarium specimens (including type material) of Cremanthodium principis and C. gypsophilum has revealed that the two species are morphologically very distinct from each other. We therefore reinstate the independent specific status of C. gypsophilum which has been placed in synonymy with C. principis. The latter species is currently known only from the holotype, and all the other specimens previously identified as C. principis should belong to C. gypsophilum.
Cremanthodium weixiense (Asteraceae, Senecioneae), a new species from northwestern Yunnan, China, is described and illustrated. The new species is referred to C. ser. Calcicola based on its palmately veined leaves, discoid capitula and leaflike, herbaceous phyllaries. However, it is unique in this series in having dissected leaves. It is somewhat similar to C. pinnatisectum in C. ser. Campanulata in the dissected leaves and the discoid capitula, but differs by the suborbicular (versus subreniform) basal leaves with deeply cordate (versus subtruncate) bases and very narrow (versus obviously divergent) sinuses, the presence (versus absence) of a conspicuously sheathed petiolar base of stem leaves, the broadly cylindrical (versus campanulate) involucres and the leaflike, herbaceous (versus petaloid, membranous) phyllaries.
Ammonia toxicity varies largely due to its pH- and temperature-dependent speciation (unionized ammonia nitrogen, NH3-N). The seasonal and long-term trend of ammonia risk in ecologically significant sections of Tai Lake, China was unknown. In this study, a two-level (deterministic and quantitative) method was developed to assess the special ecological risks posed by NH3-N at 37 sites during two seasons (February and September) of 2014 in Tai Lake. The long-term temporal (2004–2015) risk posed by NH3-N was also assessed by comparing annual quantitative risk values (probability of exceeding acute or chronic threshold values) in three key sections of Tai Lake. The results indicated the species living in the Tai Lake were at a 0.04% and 32.45% chance of risk due to acute exposure, and a 1.97% and 92.05% chance of risk due to chronic exposure in February and September of 2014, respectively. Alarmingly, the chronic ecological risks of NH3-N in the Lanshanzui section of the Tai Lake remained > 30% from 2004 to 2011. The chronic risk of NH3-N in all three key sections of Tai Lake started to decrease in 2011. This was likely the consequence of the control practice of eutrophication implemented in the Tai Lake. A significant decline in diversity of the benthic invertebrate community of the Tai Lake could be associated with continuous exposure to ammonia over decades given different sensitivity of taxa to ammonia. The results laid a scientific foundation for risk assessment and management of ammonia in Tai Lake, China, and the developed two-level risk assessment approach can also be applied to other similar aquatic regions.
Arsenic (As) is a common trace element whose oxidation states mainly include four types (− 3, 0, + 3, and + 5), and inorganic As(III) and As(V) are regarded as the most commonly existing forms in aqueous environments. Generally, As(III) has a higher toxicity than As(V) due to the different mechanisms in arsenic toxicity. However, there are few studies about the water quality criteria (WQC) of As(III) and As(V) respectively because of the deficiency of arsenic toxicity data coming from diverse taxonomic groups. In this research, eight native Chinese aquatic organisms were adopted to conduct toxicity tests for As(III) and As(V) to supplement the published toxicity data. The species sensitivity distribution (SSD) method on the basis of the Log-normal model which was the most optimal among eight models was applied to derive WQCs of As(III) and As(V). Results showed that crustaceans were the most sensitive to As(III) and As(V) among all tested species, thus they could be a biological indicator, and the influence of pH values on arsenic toxicity was complex and species-specific. Besides, the sensitivity differences between native and non-native species were observed. Finally, a criterion maximum concentration (CMC) of 167 and 384 μg/L for As(III) and As(V), and a criterion continuous concentration (CCC) of 42 and 44 μg/L for As(III) and As(V) were derived using native species, regardless of pH values. The WQCs were also verified by other two methods of ETX 2.0 and species sensitivity rank.
Hexabromocyclododecane (HBCD) is a brominated flame retardant used throughout the world. It has been detected in various environmental media and has been shown toxic to aquatic life. The toxic effects of HBCD to aquatic organisms in Chinese freshwater ecosystems are discussed here. Experiments were conducted with nine types of acute toxicity testing and three types of chronic toxicity testing. After comparing a range of species sensitivity distribution models, the optimal model of Bull III was used to derive the safety thresholds for HBCD. The acute safety threshold and the chronic safety threshold of HBCD for Chinese freshwater organisms were found to be 2.32mg/L and 0.128mg/L, respectively. Both values were verified by the methods of the Netherlands and the United States. HBCD was found to be less toxic compared to other widely used brominated flame retardants. The present results provide valuable information for revision of the water quality standard of HBCD in China.
