Drosera amazonica — Vorstman's Guide to the Carnivorous Plants

Identification

A small rosette of semi-erect leaves at the end of a short, unbranched stem that can reach 10 to 14 cm. The leaves have a petiole 5 to 10 mm long and 1 to 3 mm wide and a spoon-shaped to ovate blade only 2.5 to 5 mm long and 1 to 3 mm wide, set with tentacles. Forming a stem is a characteristic difference from many other small lowland sundews. A confirmed flower colour could not be checked here.

Similar species

Drosera biflora, Drosera sessilifolia and Drosera cayennensis also grow in the white-sand savannas of northern Amazonia. D. sessilifolia has broad, sessile wedge-shaped leaves; D. cayennensis and D. biflora usually form a flat rosette without a distinct stem. The combination of an elongated stem with small spoon-shaped leaves and a floodplain habitat points to D. amazonica.

The trap and how it works

An active flypaper trap on a small scale. The tentacles catch minute insects; the semi-erect leaves at the stem tip catch both crawling and low-flying prey. In the wet period, when the surroundings are partly flooded, gnats and other small flying insects are abundant.

Habitat and ecology

Seasonally flooded, open places on white sand in the northern Amazon basin: sandy banks, white-sand savannas and clearings in the floodplains, which flood in the rainy season and fall dry in the dry season (W7, D1, B6). The stem may keep the rosette above rising water or competing vegetation.

Distribution and elevation

Northern Brazil, in the floodplains of the northern Amazon basin, in the states of Amazonas and Roraima. As far as known endemic to Brazil, but similar white-sand areas extend into Venezuela and Colombia, so further finds across the border cannot be ruled out.

Recorded (one-degree cells)

Distribution based solely on records at GBIF (Global Biodiversity Information Facility), not on TDWG regions — those are often far larger than the actual range. The light halo is the area around a record, the dark core the record itself. The darker cells are 2 one-degree squares — roughly a hundred and ten kilometres — in which the species has been recorded, from all GBIF records. This is coarser than for most species because hardly any record of this plant carries an accurate coordinate: the locality of poached species is obscured at source. At this scale that obscuring disappears into the noise. The cells show where it has been seen, not where it occurs: an empty square means nothing.

Forms and variation

No varieties are recognised. The species is a good example of a recent discovery in an area that remains botanically poorly explored. The adaptation of the seed to water dispersal fits the ecology of flooded forests and savannas, where many plants let the water carry their seed.

Where and when to see it

The best time is the start of the dry season, when the floodplains fall dry and the sandy banks are exposed. Search open white-sand patches along rivers and in savannas near rivers in Roraima and Amazonas. The plants are small; a hand lens is useful.

Conservation status

Not assessed for the global IUCN Red List and not listed in CITES. Little is known about numbers and trends. The habitat depends on the natural flood rhythm of the rivers; dams, deforestation and gold mining in the catchments can disrupt that rhythm and with it the sites.

Scientific name

Drosera amazonica | Rivadavia, Fleischmann & Vicentini, 2009

Described by Fernando Rivadavia, Andreas Fleischmann & Alberto Vicentini in 2009, in "A new species of sundew (Drosera, Droseraceae) with water-dispersed seed, from the floodplains of the northern Amazon basin, Brazil", Ecotropica, volume 15, no. 1-2, p. 13-21. Brazil, Amazonas state, Rio Cuieiras, igarapé de Cachoeira, collected 15 November 1964, Rodrigues 6042 (holotype at INPA herbarium, no. INPA-15093). The species occurs in the Brazilian states of Amazonas and Roraima, also recorded in Venezuela. Named after the Amazon basin, the region where the species occurs, also referenced in the publication title.

World Checklist of Vascular Plants (WCVP), via Plants of the World Online (POWO), Royal Botanic Gardens, Kew.