Drosera australis, Drosera pulchella, & Drosera sargentii

Drosera australis

I recently ran across a really cool blog about wildflowers in the Esperance, Western Australia area. Happily, it includes lots of information about carnivores, including three diminutive Drosera - australis, pulchella, and sargentii. It is not unusual to find these three species growing together on sandy berms above flooded swamps. Drosera pulchella is often nearest the water. Drosera australis occupies the damp zone just above the one occupied by Drosera pulchella. Drosera sargentii occupies the highest area, often on level hilltops where rainwater soaks into the soil and keeps it moist.

Drosera pulchella

D. australis is very common along the south coast from Augusta to Israelite Bay, where it grows in sandy soils, simetmes with high humus content. D. pulchella, in contrast, often grows in the soil which is inundated by rainfall during the rainy season. Its seeds germinate when the surface water has evaporated and, in Esperance, is an annual due to the harsh conditions (it is a perennial elsewhere). In Esperance, D. australis usually has one flower, but can have up to three, and often congregate to produce large clumps. D. pulchella, in contrast, produces one to four flowers.

Drosera sargentii

Much like D. australis and D. pulchella, D. sargentii is very common around Esperance in near coastal, non-calcareous, deep white sands. As with other pygmies, fires keep the habitat of D. sargentii from becoming too overcrowded by competing plants. (The diminuative Drosera are easily overshadowed by other plants). As with D. australis and D. pulchella, D. sargentii has fewer flowers in the harsh Esperance region than elsewhere (elsewhere it can have up to 50 flowers).