Drosera filiformis var. filiformis
D. filiformis var. filiformis from Nova Scotia, Canada
Range: Mideastern US coast and Canada
The standard form of the threadleaf sundew is a spectacular and widespread, if disjunct, species, growing as far north as Nova Scotia but also recorded in the coastal New England states (Massachusetts to New Jersey) as well as in North Carolina; while each region has slightly different appearances due to local adaptation and drift, they are all considered genetically and physically similar enough to remain as one variety (perhaps better recognized however as a subspecies due to geographic separation from var. floridana). They are typically found in sandy soils that remain above the water line, slightly drier and without sphagnum growth being particularly present. Plants may grow to 30 cm tall, though average between 10-25 cm, filiform in structure with a very short to nonexistent petiole and slender, mildly tapered lamina ending in a very narrow tip. The tentacles are typically as long as the lamina is wide or longer, and coloration is green or yellowish to orange with red-tipped to solid red tentacles, lending an overall orange or reddish appearance to plants in good light. Inflorescences may reach 30 cm tall as well, usually slightly taller than the leaves, bearing a few to over a dozen 1-2.5 cm wide flowers with oblong to obovate petals of varying shades of pink. This variety is distinguished from the Florida variety by range, but also by being less densely red and usually larger overall, and is distinguished from its relative D. tracyi by its smaller and more upright growth habit, reddish overall coloration, and longer tentacles relative to the leaf width.
Cultivation: best grown in a sandy peat soil (ratio approx. 2:1), kept moist but preferably not wet or dry and with moderate humidity, temperatures between 60-85°F during the growing season. When plants go dormant and form hibernacula in winter, place in a cool to cold location (and keep moist) for at least 3 months or until spring. Cold-stratify seeds for 4-12 weeks before sowing on the soil surface, and grow in strong artificial light to full sun.
Lifespan and reproduction: perennial. Reproduces by seed and can be grown by cuttings and division.
Sources: Lowrie et al. (2017) Drosera of the World Vol. 2
Close-up of the flower from D. filiformis Nova Scotia; these are the largest North American sundew flowers behind D. tracyi, with highly glandular sepals.
The cultivation details pertaining to seed treatment above are the general recommendations given by most sources; unfortunately this species is one that remains enigmatic for me, and even fresh seeds from my own plants I frequently find failure with, the reason unknown. If you know of any surefire ways to get germination, I would love to add it here (and use it, as there are rare forms that I need to germinate).
D. filiformis var. filiformis "typical," a variant without locality that displays average traits for this taxon.
D. filiformis var. filiformis from Lakehurst, New Jersey; this region is a stronghold for populations of the species, with many localities both in trade and still preserved in the wild, especially in the Jersey Pine Barrens.