Skip to main content

Mount Ayanganna bonnetia (Bonnetia ayangannensis) from the Pantepui of western Guyana, South America

Mount Ayanganna bonnetia (Bonnetia ayangannensis) from the Pantepui of western Guyana, South America

NEWS - Researchers describe Mount Ayanganna bonnetia (Bonnetia ayangannensis) from the summit of Mount Ayanganna tepui in Guyana, in terms of morphology, distribution, micromorphological characterization under scanning electron microscopy, leaf venation and comparison with closely related species.

Bonnetia Mart. is the most representative genus of the woody flora of Pantepui and one of the groups with the greatest endemism in the local flora. The genus has 32 species currently known in tropical America. This study adds Bonnetia ayangannensis and the number of endemics in Pantepui to 27 species.

Micromorphological analysis of the leaves shows serrated margins, sometimes with deciduous spinular protrusions. The abaxial leaf surface is rough and has numerous sessile glands and stomata. At higher magnification, the surface appears warty-crusty with granular protrusions.

The margins of the bracts have short-stalked glands with thin-walled elongated heads. The petals have short-stalked glands on the outer surface and short-stalked glands on the margins. Seeds have longitudinal stripes.

B. ayangannensis closely resembles B. paniculata, but differs in leaf blades (1-)1.5-4 cm (vs. 6-18 cm), leaves with glandular punctuations on abaxial surface (vs. glands absent), bracts 2-3 mm (vs. 6-7 mm), sepals ciliated and glandular (vs. ciliated and glands absent) and 2-4 × 1-2 mm (vs. 10 mm × 6-7 mm).

B. ayangannensis differs from B. tepuiensis and B. rubicunda by having leaves that are wedge-shaped at the base (vs. rounded in B. tepuiensis), stalked flowers (vs. sessile), arranged in inflorescences (vs. solitary flowers), pinnate venation, flowers with sepals and petals less than 8 mm long (vs. parallel venation, sepals and petals more than 18 mm long in B. rubicunda).

The epithet refers to Mount Ayanganna, where the new species was discovered and is known only from two collections collected at close range from a single population on the eastern summit slope. It occurs in scrub forest on sandstone, together with B. tepuiensis, Clusia spp. and Brocchinia spp. at elevations of 1900-2000 meters.

The researchers recommend B. ayangannensis be placed in the Critically Endangered category. The species is primarily known from two locations separated by only about 0.06 km over an area of 4 km2. However, considering that at 1900 meters the actual area is thought to be much smaller. In addition, anthropogenic climate change is a serious threat to habitats in the highlands.

Original research

Barbosa-Silva RG, Torke BM, Viana PL (2024). A new species of Bonnetia Mart. (Bonnetiaceae) from the Pantepui of South America. PhytoKeys 247: 55-65, DOI:10.3897/phytokeys.247.126950

Dlium theDlium

Popular Posts

Cockspur coral tree (Erythrina crista-galli)

Velvet coral tree or cockspur coral tree ( Erythrina crista-galli ) is a species of plant in the Fabaceae family. It is a small tree, 5-8 meters tall, with a trunk circumference of about 50 cm, irregular branches, light wood, and fissured, soft, and light brown bark. The taproot is white. The leaves are ovate, with three strands, dark green and glossy on the upper surface, and pale green on the underside. The central lobe is up to 17 cm long and up to 11 cm wide. The left and right lobes are up to 15 cm long and up to 10 cm wide. The flowers are red, arranged in racemes, at the apex, pentameric, complete, and bilaterally symmetrical. The flowers are up to 6 cm long and 4 cm wide. The pods are long, containing about 8 seeds, green when young and turning brown as they mature. The seeds are ovate, flat, and brown. It grows well in lowlands up to an elevation of 1,500 meters, with an annual rainfall of 800-1,500 mm/year, and a temperature of 20-32°C. It thrives in well-drained soils, but...

Javan broadhead planarian (Bipalium javanum)

Cacing palu or Javan broadhead planarian ( Bipalium javanum ) is a species of animal in Geoplanidae, hermaphrodite, living on the ground, predators, often called only hammerhead or broadhead or shovel worms because of wide heads and simple copulatory organs. B. javanum has a slim stature, up to 20 cm long, up to 0.5 cm wide, head wide up to 1 cm or less, small neck, widening in the middle and the back end is rounded, all black and shiny. Javan broadhead planarians walk above ground level by raising their heads and actively looking left, right and looking up using strong neck muscles. Move swiftly, track meander, climb to get through all obstacles or make a new path if the obstacle is too high. Cacing palu track and prey on earthworms and mollusks. They use muscles and sticky secretions to attach themselves to prey to lock in. The head and ends of the body are wrapped around and continue to close the body to stop prey reactions. They produce tetrodotoxins which are very strong...

Serrated pimpernel (Lindernia glandulifera)

Serrated pimpernel ( Lindernia glandulifera ) is a species of plant in the Linderniaceae family, erect, 8-9 cm long.and white roots. The stems are cylindrical or angular or curved inward. The stems green or dark red or reddish brown. The leaves are opposite, green or dark red or brown, oval or oblong, up to 3 cm long, up to 1 cm wide and serrated margins. The flowers are white and blue, 0.6-0.7 cm wide. This plant grows in colonies in karst areas, clay soils, and areas that are sometimes flooded. TAXON Kingdom: Plantae Phylum: Tracheophyta Subphylum: Angiospermae Class: Magnoliopsida Order: Lamiales Family: Linderniaceae Genus: Lindernia All. in Auct. Syn. Meth. Stirp. Hort. Regii Taur. 3: 178 (1766) Species: Lindernia glandulifera (Blume) Backer in Onkruidfl. Jav. Suikerrietgr.: 616 (1930) VERNACULAR NAME English: Serrated pimpernel Indonesia: Tapak gergaji Java: Tapak graji Aryo Bandoro Dlium TheDlium Web: https://www.dlium.com YouTube: https://www.youtube.com/@Dlium