Drosera echinoblastus — Vorstman's Guide to the Carnivorous Plants

Identification

A perennial, fibrous-rooted pygmy sundew that can reach 12 cm with its flowering stem, large for a pygmy sundew. The heart of the rosette carries the cone of silvery stipules. The flowers are orange and appear late, in October and November. The characteristic detail is the gemmae formed at the centre of the rosette at the end of autumn: in this species they have a spiny, knobbly surface. Precise leaf and flower measurements were not available in the accessible sources.

Similar species

Its counterpart is Drosera leioblastus, described in the same publication, which has smooth gemmae. Several other pygmy sundews flower orange, including Drosera callistos, which flowers in the same months but grows on lateritic soil, and Drosera barbigera and Drosera miniata, which flower earlier in the season. The spiny gemmae are the best character outside flowering, although they are present only in autumn and winter.

The trap and how it works

An active flypaper trap. The small leaves bear stalked glands with droplets of glue in which small insects are caught; the tentacles bend towards the prey and secrete digestive enzymes. On the damp sandy soil where the species grows, springtails and small gnats are the main prey.

Habitat and ecology

Sandy soils in places that are damp in winter (FloraBase): depressions and flat parts of the sandplains where water stands or sits high in the soil during the wet season (W7, D1). The late flowering fits the late drying of these sites.

Distribution and elevation

Endemic to the south-west of Western Australia. FloraBase lists the Geraldton Sandplains and Swan Coastal Plain bioregions, in the Lesueur Sandplain and Perth subregions.

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 6 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 subspecies or varieties have been described. Reproduction by gemmae is especially conspicuous in this species because of their spiny form. The gemmae are splashed out of the heart of the rosette by raindrops and grow into new plants.

Where and when to see it

For the flowers: October to early November, in the damp depressions of the sandplains. For the gemmae: come in winter, June or July, and look into the heart of the rosette with a hand lens. To see both features you will have to visit the site twice.

Conservation status

Assessed as Least Concern (LC) on the IUCN Red List and listed as not threatened in Western Australia. Not in CITES. The sandplains north of Perth are under pressure from clearing and falling groundwater, but large protected heathland areas lie within the range.

Scientific name

Drosera echinoblastus | Marchant & Lowrie, 1992

Described by N.G. Marchant & Allen Lowrie in 1992, in "New Names and New Combinations in 34 Taxa of Western Australian Tuberous and Pygmy Drosera", Kew Bulletin, volume 47, no. 2, p. 322 (29 June 1992). South-western Australia, with two cited localities: near Hill River, north of Cataby, and at Cranbrook, Western Australia. Greek for "spiny" or "hedgehog-like" — refers to the plant's spiny, hedgehog-like resting bud (turion).

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