About Drosera anglica Huds.
Drosera anglica Huds., the English sundew, is a perennial carnivorous herb that forms an upright, stemless rosette of generally linear-spatulate leaves. Like all sundews, its leaf blades (laminae) are densely covered with stalked reddish mucilaginous glands, each tipped with a clear droplet of viscous fluid used to trap insects. The lamina itself measures 15–35 millimetres (0.59–1.38 in) long, and is held semi-erect by a long petiole, bringing the total leaf length to 30–95 millimetres (1.2–3.7 in). Plants are normally green, but turn red when grown in bright light. All populations except those found on Kauaʻi form winter resting buds called hibernacula: these are knots of tightly curled leaves that sit at ground level, and unfurl in spring once the dormancy period ends. The root system of Drosera anglica is weak, and only penetrates a few centimeters into soil; it functions mainly as an anchor and for water absorption. Because nitrogen is typically scarce in the bog habitats this plant occupies, trapping and digesting insects supplies it with an alternate source of nitrogen. Drosera anglica flowers in summer, sending up 6–18 centimetres (2.4–7.1 in) long peduncles that hold several white flowers, which open one at a time. Like other sundews, its flowers have five sepals, five petals, five stamens, and three styles. For this species, petals are 8–12 mm (¼ to ½ inch) long, and the flowers have branched 2-lobed styles. The flowers are odorless and produce no nectar; they do not rely on insect pollinators, and instead set ample seed through self-pollination (autogamy). Seeds are black, roundish and spindle-shaped, and measure 1 to 1+1⁄2 mm long. Fruits are dehiscent three-valved capsules. Drosera anglica grows in open, non-forested habitat with wet, often calcium-rich soils. Common habitats include bogs, marl fens, quaking bogs, cobble shores, and other calcareous sites. This tolerance for calcium is relatively rare among other species in the Drosera genus. D. anglica is often associated with various sphagnum mosses, and frequently grows in a soil substrate made entirely of living, dead, or decomposed sphagnum. Sphagnum wicks moisture to the soil surface while simultaneously acidifying the soil. Any soil nutrients not leached away by constant moisture are usually either used up by sphagnum or made unavailable by low soil pH. Since nutrient availability is low, competition from other plants is reduced, which allows this carnivorous sundew to grow well. Drosera anglica is one of the most widely distributed sundew species in the world. It is generally circumboreal, meaning it is found at high latitudes across the globe. It also occurs farther south in a few areas, specifically in Japan, southern Europe, the Hawaiian island of Kauaʻi, and California. Plants from Hawaiʻi, where the species is called mikinalo, are generally smaller than average and do not go through a winter dormancy period. Its natural range covers 12 U.S. states (including Alaska) and 11 Canadian provinces and territories. Its altitudinal range spans from 5 metres (16 ft) to at least 2,000 metres (6,600 ft). In the U.S. state of Minnesota, it was recorded growing in 1978 in shallow pools in peatlands with minerotrophic water, where the plant community was dominated by low-growing mosses and sedge species. Because it only occurs in small, limited populations and occupies very specific microhabitats in the state, it is listed as a threatened species in Minnesota.
