8 research outputs found
FIGURE 1. Anadendrum latifolium. Fruiting twig, from P. Chakraborty 5614 in Notes on the distribution of Anadendrum latifolium (Araceae) in India and its lectotypification
No full textFIGURE 1. Anadendrum latifolium. Fruiting twig, from P. Chakraborty 5614. Drawn by Dineshwar Kumar Sah.Published as part of Rasingam, Ladan & Karthigeyan, Kaliyamurthy, 2021, Notes on the distribution of Anadendrum latifolium (Araceae) in India and its lectotypification, pp. 149-152 in Phytotaxa 500 (2) on page 150, DOI: 10.11646/phytotaxa.500.2.9, http://zenodo.org/record/542453
Anadendrum latifolium Hooker 1893
No full textAnadendrum latifolium Hook. f. (1893: 540). (Fig. 1) Type:— PENINSULAR MALAYSIA. Perak, without date, B. Scortechini, 577b (lectotype K000401076, image!, designated here). Fig. 2. Slender evergreen medium sized hemi epiphytic herbs to 3 m. Juvenile shoots stoloniferous, 4–6 mm in diam., with conspicuous nodes giving a segmented appearance; internodes cylindrical, 3–7 cm long, rooting. Adult shoots climbing; stem cylindrical, 4–6 mm diam., segmented in appearance; internodes 2.0– 3.5 cm long, drying dark brown. Leaves distichous, scattered; petiole 15–28 cm long, narrowly sheathing; sheaths c. 2/3 as long as the petiole, 3–6 mm wide, membranous, glabrous; leaf blade oblong, 25–35 × 10–15 cm, acute at base, entire along margins, cuspidate – acuminate at apex (acumen 2.5–3.0 cm long), chartaceous, glabrous; lateral veins 12–15 on each side, prominent, 1.5–2.0 cm distant, spreading and arched. Inflorescence axillary, 2–3 in each floral shoot; peduncle spreading, cylindrical, 15–25 cm long, glabrous. Fruit a berry, ovoid, 8–10 mm long, distinctly truncate at apex, thick walled, smooth, red on ripening, dark brownish when dry. Flowering & Fruiting:— April-July. Distribution:— India: Katchal Island, Andaman & Nicobar Islands; China, Indo-China, Indonesia, Malaysia and Philippines. Habitat:— Common in shaded inland forests. Specimen examined:— India, Andaman & Nicobar Islands, Katchal Island, East Bay, 7 th May 1977, P . Chakraborty 5614 (PBL!). Notes:— Hooker (1893) described Anadendrum latifolium based on the three collections viz., Scortechini 577b and Kings’ collector 5961 & 8323 collected from the Perak region of Malay Peninsula. There are 6 specimens available in 4 herbaria viz., Scortechini, B ., Coll. No. 577b [K000401076]; King’s collector, Coll. No. 5961, [K000401077, image!; SING 0043211, image!], King’s collector, Coll. No. 8323 [K000401078, image!, BM000957215, image!] and a single herbarium sheet (possibly the Scortechini collection without any number) with a line drawing and a collection number of 577b is available at CAL. Of these, the better preserved specimen K000401076 from Kew herbarium, is designated here as the lectotype as it agrees well with the protologue.Published as part of Rasingam, Ladan & Karthigeyan, Kaliyamurthy, 2021, Notes on the distribution of Anadendrum latifolium (Araceae) in India and its lectotypification, pp. 149-152 in Phytotaxa 500 (2) on pages 149-151, DOI: 10.11646/phytotaxa.500.2.9, http://zenodo.org/record/542453
A new species of Tripogon (Poaceae: Chloridoideae: Tripogoninae) from Nallamala forests, Telangana, India
No full textA new species Tripogon nallamalayanus is described from Nagarjunasagar Srisailam Tiger Reserve of Nallamala forests, Telangana, India. This new species most closely resembles Tripogon trifidus, but differs in spikelets and lower glumes lengths and lemma and palea shapes.</jats:p
Crotalaria nallamalayana (Fabaceae: Crotalarieae): a new species from Telangana, India
No full textA new species of Crotalaria is described from the Amrabad Tiger Reserve in the Nallamala forest, Telangana, India. It is allied to Crotalaria orixensis Rottl. ex Willd. and Crotalaria senegalensis (Pers.) DC., but differs from both species in leaf, stipule, bract and floral characters.</jats:p
Validation of the name Amorphophallus candidissimus (Araceae)
No full textWhile identifying a species of Amorphophallus Blume ex Decaisne (1834: 366), nom. cons. collected from the Kadapa district of Andhra Pradesh, India, the authors came across the protologue of Amorphophallus candidissimus X.Gong & H.Li (2012: 201) described from Vietnam, but it was not validly published, as two different collections (leaf and inflorescence) collected in two different dates were indicated as “holotype” in contrary to Art. 8.1 and 40.2 (see Ex. 1) of the Melbourne Code (McNeill et al. 2012). Hence, the name A. candidissimus is validated here by designating a single collection (flowering material) as a holotype. The other collection (leaf material) is considered as a paratype, as it also depicts one of the diagnostic characters (lamina lacking bulbils) of the species.</jats:p
Tropical cyclones and island area shape species abundance distributions of local tree communities
No full textSpecies abundance distributions (SADs) characterise the distribution of individuals among species. SADs have rarely been explored on islands and the ecological processes shaping SADs are still not fully understood. Notably, the relative importance of disturbance regime in shaping plant SADs remains poorly known. We investigate the relative importance of disturbance regime and island geography on the shape of SADs. We computed SADs for local tree communities in 1-ha forest plots on 20 tropical islands in the Indo-Pacific region. We used generalized linear models to analyse how the shape parameter of the gambin SAD model was related to the number of trees and the number of species. Regression analyses were also used to investigate how the shape of SADs, the number of trees and the number of species were related to cyclone disturbance (power dissipation index) and geography (island area and isolation), with direct and indirect (i.e. through the number of trees and species) effects assessed using variance partitioning. Cyclone disturbance was the best predictor of the shape of SADs, with higher power dissipation index producing more lognormal-like distributions. This effect was mostly due to cyclones increasing the number of trees and decreasing the number of species. Island area affected the shape of SADs through its effect on the number of species, and larger islands were associated with higher species richness and more logseries-like distributions. The effect of cyclones was stronger on smaller islands. Our results illustrate that disturbances can affect SADs in complex ways; directly and indirectly by impacting the number of species and individuals in communities, and these effects may be moderated by island-specific characteristics, such as island area or isolation. Our results therefore suggest that multiple, interacting processes shape SADs and that studying SADs has the potential to contribute important new insights to the field of island biogeography
Regional forcing explains local species diversity and turnover on tropical islands
No full textInternational audienceAim: To determine the role of regional forcing on plot-level species diversity and composition, and to quantify the relative importance of biogeographical and climatic factors in explaining woody plant diversity and composition at the local-, island- and archipelago-scale. Location: Forty-one tropical islands of the Indo-Pacific region from Madagascar to Hawai‘i Island. Methods: We analysed the diversity and composition of tropical woody plant communities located across 113 plots, 41 islands and 19 archipelagos. We used generalized linear mixed-effects models and generalized dissimilarity models to determine the role of regional forcing at the island and archipelago scale and to assess the relative importance of biogeographical (area and isolation of islands or archipelagos, geographical distance between plots) and climatic factors in explaining differences in local diversity and composition (species turnover). Analyses were conducted at different geographical scales (local, island and archipelago) and taxonomic levels (species, genus and family). Results: Variation in local (plot-level) diversity (as species density, the number of species per 100 woody plants) was primarily explained by island and archipelago identity. Maximum species density was positively correlated with the area of an island (or archipelago) and negatively correlated with the isolation of an archipelago. Local climatic variability was also a significant predictor of species density, but less important than regional forcing. Climate variables explained < 20% of the variation in species turnover across all plots. The importance of geographical distance between plots relative to climate in driving species turnover decreased from the species to family level, and from the regional to island level. Main conclusions: Regional forcing was the key driver of local diversity and composition on islands. Island area and archipelago isolation are likely driving local diversity through their effects on the pool of island species. Geographical distance between plots is the main factor explaining species turnover, while at higher taxonomic levels, climatic factors and niche conservatism are the main drivers
Analogous Environments Across the Tropics Have Similar Levels of Tree Species Αlpha Diversity
No full textDifferent regions of the tropics vary in overall tree species diversity, with the tropical Americas exhibiting strikingly higher regional tree species richness than Africa and Southeast Asia. We investigated whether these differences also occur at the local scale, and whether the environmental conditions associated with tree species richness are consistent across tropical regions despite highly dissimilar species pools. A spatial random forest (RF) model was trained using a network of 429 one-hectare plots across the tropics, together with 24 environmental variables, to predict plot-level tree α diversity. A combination of climatic, soil and topographical variables explained around 86% of variation in richness. Despite differences in regional species pools and potentially disruptive effects of different geological, climatic and evolutionary histories, the relationship between environmental variables and local scale tree species richness is closely similar across different continents. Our findings imply a pervasive role of niche-based mechanisms in structuring local tree species richness, regardless of regional species assemblages. This pantropical convergence in the richness-environment relationship poses a challenge for ecology to explain
