Drosera tokaiensis

D. tokaiensis.jpg

Drosera tokaiensis var. tokaiensis

Range: Central Honshu, Japan

 

Originally thought to be a subspecies of D. spatulata, this plant is now known to be a polyploid species originating from a natural hybrid between D. rotundifolia x spatulata, and has since stabilized since undergoing allopolyploidy as its own taxon. It is recorded from the primary island in the Japanese archipelago, from sea level up to several hundred meters in elevation, and is typically found in mossy hummocks, marshy regions, or sandstone-based substrates. Plants average around 3-5 cm in diameter and develop flat rosettes of spatulate leaves, with a distinct narrow though often slightly tapered petiole typically half to two-thirds the length of the whole leaf that often gradually expands at the end into a broad semi-obovate or orbiculate lamina. Some forms have a more distinct cutoff in tentacle growth on the lamina to the petiole, others have a gradual reduction in gland presence onto the petiole. Coloration varies from rich green with red tentacles to solid red under full sunlight. Inflorescences may reach up to 20 cm tall (usually somewhat shorter) and may number up to 5 or more in a season, moderately glandular along their length, and bear between 4-12 flowers each. Flowers have roughly ovate sepals with a blunt tip, and are approximately 1-1.5 cm across on average with hot pink, rotund petals with a slight truncation at their tips. Frequently confused in cultivation even by the most respected nurseries in the carnivorous plant trade with D. spatulata, this species is distinct from its relatives in possessing significantly more and more ragged divided tips on its stipules, broader more rounded lamina than most common spatulata forms, thicker and more blunt-tipped sepals on a less glandular scape, more rounded petals (and flower buds overall when unopened), fewer flowers per scape but often more scapes at a time, and typically longer petioles relative to the length of the leaf overall. All natural forms are also pink-flowered; white-flowered horticultural and fertile forms are rare.

 

The first generation hybrid between the parent species still is occasionally recorded in the wild and is infertile, currently also common in cultivation (where it can be recognized by its lack of seed production, mounding habit which may be the result of tissue-culture hormonal influence, and frequently bifurcated flower stalks with blooms that are less willing to open) and is referred to as D. tokaiensis hyugaensis (though should be published as a separate taxon altogether as, being sterile, it is incapable of interbreeding with D. tokaiensis var. tokaiensis or either of the original parent species and thus an equally distinct and true nothospecific taxon).

 

Cultivation: grow in any suitable carnivorous plant soil (personal recommendation is 1:1 peat/perlite or sand), kept very moist and relatively humid, with temps of 65-90°F year round. If subjected to low temperatures, plants of some lineages may go dormant. Sow seeds on soil surface, and grow in strong artificial light to full sun.

 

Lifespan and reproduction: perennial. Reproduces through seeds (except for var. hyugaensis), and can be grown through cuttings and division.

 

Sources: Nakano, M., Kinoshita, E., and Ueda, K. (2004). Life history traits and coexistence of an amphidiploid, Drosera tokaiensis, and its parental species, D. rotundifolia and D. spatulata (Droseraceae). Plant Species Biology 19: 59-72.

https://www.carnivorousplants.org/cp/taxonomy/Droseraspatulata

Drosera tokaiensis hyugaensis.jpg

D. tokaiensis var. huygaensis. This variety, though genetically unique with only half the chromosomes compared to the nominate form and thus should be described separately, is often physically indistinguishable from the fertile species.