Practical ecological knowledge for the temperate reader.

Trientalis Sp. - Starflower

Family: Myrsinaceae (Myrsine) [E-flora]

3 species: North America, n Eurasia [Jepson 1993]
2 species: T. borealis & T. europaea. 3 subsp. []

"Perennial herbs, from slender or tuberous rhizomes. Stems erect, simple, glabrous. Leaves mostly in a terminal whorl or cluster (primary leaves), dimorphic, sessile to short-stalked; primary leaves lanceolate to broadly obovate or spatulate, entire, glabrous; stem leaves reduced or scale-like. Flowers long-stalked, solitary, axillary in uppermost leaves. Flowers 1-several per plant; corollas rotate, 5- to 9-lobed, white to pinkish; calyces green, deeply 5- to 9-lobed, the lobes linear-lanceolate to lanceolate; stamens 5-9; filaments partly connate. Fruits globose capsules, valvate; seeds black to reddish-brown, with a deciduous, white, net-like coating. 3 spp. (2 spp. in B.C.). North America, Eurasia." [VFBC-E-flora]

"Species of Trientalis are all very closely related, and the number of species recognized in the genus has ranged from one to four in the past. It is closely related to Lysimachia, and, like several other genera in Myrsinaceae, its recognition make traditional circumscriptions of that genus paraphyletic; monophyly in Lysimachia and Trientalis is apparently maintained with the recognition of Steironema (Manns and Anderberg 2005), as is done here. Note that, in this treatment, the leaves that comprise the pseudowhorl subtending the inflorescence are termed primary leaves, while the reduced leaves below this pseudowhorl are termed stem leaves.
" [VFBC-E-flora]

Local Species;

  1. Trientalis latifolia - Northern Starflower [E-flora]
  2. Trientalis europaea - northern starflower [E-flora]


1. Primary stem leaves lanceolate, oblanceolate or egg-shaped, rather abruptly sharp-pointed to blunt, 1-5 (8) cm long; reduced leaves scattered along stem below the terminal whorl; corollas usually white, 10-16 mm wide; flower stalks longer than main leaves; tubers not conspicuously enlarged, horizontal.....................T. europea ssp. arctica [IFBC-E-flora]

1. Primary stem leaves broadly egg-shaped to elliptic, gradually tapering to sharp points, 3-10 cm long, all others reduced to tiny bracts along the stem below the terminal whorl, corollas pinkish to rose, or somewhat pinkish-lavender, 8-15 mm wide; flower stalks shorter than leaves; tubers 1-2 cm, ascending to erect.................T. borealis ssp. latifolia [IFBC-E-flora]


Trientalis sp. contain saponins. [MPP1]

Edible Uses

Other Uses

Medicinal Uses

Trientalis latifolia - Northern Starflower

"General: Plants from a usually vertical tuber; tuber 1-2 cm." [VFBC-E-flora]

"Habitat / Range Moist to mesic coniferous forests, mixed woodlands, and riparian areas in the lowland and montane zones. Common in sw BC (Vancouver Island, southern mainland coast), rare and local in wc and c BC; south to CA, ID; disjunct in YT." [VFBC-E-flora]

"Additional Notes No combination for Trientalis latifolia in Lysimachia has been proposed, so no names are available for the species if it is moved to that genus. This is a common forest herb in southwestern B.C., where it can be found in a wide variety of woodland habitats; it is considerably less common elsewhere in B.C. A very similar species, Trientalis borealis Raf. (BOREAL STARFLOWER), occurs throughout most of the boreal regions of Canada east of the Rocky Mountains, occurring west to northern Alberta; it may occur in extreme northeast BC. It has narrower primary leaves than T. latifolia (lanceolate or lanceolate-elliptic, rather than broadly elliptic to nearly orbicular), with fewer flowers per plant (1-3) and consistently white corollas (corollas usually pink or pink-tinged in T. latifolia). Some plants of T. latifolia (particularly on Vancouver Island) approach T. borealis in leaf shape and corolla colour; however, the two species have widely allopatric distributions and are not known to occur together, which greatly facilitates their identification." [VFBC-E-flora]

"Ecological Indicator Information A shade-tolerant/intolerant, submontane to subalpine, Western North American forb distributed equally in the Pacific and Cordilleran regions. Occurs in cool temperate and cool mesothermal climates on moderately dry to fresh, nitrogen-medium soils; its occurrence decreases with increasing elevation and latitude. Scattered to plentiful on water-shedding sites, less frequent on water-receiving sites. Usually associated with Acer glabrum, Kindbergia oregana, Mahonia nervosa, and Polystichum munitum. Characteristic of young­seral forests." (Information applies to coastal locations only) [IPBC-E-flora]


Trientalis europaea - northern starflower

"Trientalis europaea is a PERENNIAL growing to 0.3 m (1ft). It is in flower from Jun to July. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Insects.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: acid and neutral soils and can grow in very acid soils.
It can grow in semi-shade (light woodland) or no shade. It prefers moist soil." [PFAF]

Subtaxa Present in B.C.

"General: Plants from a slender rhizome and a short, scarcely enlarged, horizontal tuber." [VFBC-E-flora]

"Habitat / Range Moist to wet bogs, swamps, streambanks, meadows, and coniferous forests in the lowland, montane, and subalpine zones. Frequent in coastal, nw, and se BC; AK east to NWT, south to CA, ID; Eurasia." [VFBC-E-flora]

"Additional Notes Trientalis europaea is somewhat variable throughout its circumboreal distribution, with minor variants able to persist at the population level through rhizomatous apomixis. Although this variation occurs throughout the range of the species, the species has generally been recognized as comprising two subspecies: a primarily Eurasian ssp. europaea (which apparently ranges into central Alaska) and a primarily North American ssp. arctica (Elven et al. 2013). Although the characteristics that separate these subspecies (leaf shape, leaf number, pedicel glands) are relatively minor, it is the best and most widely accepted approach for representing the variation in this species." [VFBC-E-flora]

Medicinal Use

"The root is emetic[4]. The plant was formerly esteemed as an ingredient in an ointment for treating wounds[4]." [PFAF]

Cultivation details

T.europaea; "We have very little information on this species and would suggest growing the plant in an acid soil in light shade[K]. See the plants native habitat for more ideas on its cultivation needs." [PFAF]


T.europaea; "Seed - we have no information for this species but suggest sowing the seed in spring in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in early summer. If you have sufficient seed it could be worthwhile trying an outdoor sowing in situ in mid spring." [PFAF]

Uses of Related Sp.

"Trientalis americana Pursh. (Primulaceae). American starflower. The Flambeau Ojibwa of North America mixed the roots with other species and smoked the mixture to attract deer during hunting sessions (Smith 1932)." [UAPDS]

Trientalis borealis

"Trientalis borealis Raf. (Primulaceae). starflower. The Ojibwa of North America reportedly mixed the roots of this species with other plants to produce scented smoke that was used to attract deer to hunters (Smith 1932)." [UAPDS]

Cultivation Notes

"The life cycle consists of three distinct phases each year: shoot development, rhizome growth, and tuber formation."[Anderson]

"Asexual reproduction by tubers is more important than reproduction by seed. Of the annual dry matter produced, 64.8% is apportioned to asexual reproduction and less than 2% to sexual tissue."[Anderson]

"Rhizome growth and tuber formation are regulated by photo-period; short days favor tuberization and long days favor rhizome growth. Tuber formation under field conditions began in July, when the photoperiod was about 15 hr. Cool nights and warm days were more favourable for the accumulation of dry matter than warm nights and days. The number of degree-hours accumulated during shoot development of northern and southern populations was similar at sites 200 miles apart on a north-south gradient, but shoot development occurred during a shorter period of time at the northern site. Seedlings of T. borealis have not been found in the field, but relatively high germination rates were achieved under laboratory conditions."[Anderson]

"Cold treatment increased the percentage germination of trientalis borealis seeds. Ninety days of stratification delayed the period of peak germination and increased the length of time before germination began after the seeds were exposed to room temperatures. The duration of germination and peak period of germination after stratification were about the same for controls and seeds exposed to 30- or 60-day periods of stratification."[Anderson]

"Broad environmental tolerance. Open bog to dry sandy barrens."[Anderson]

Field Phenology

"From Sept to May (Wisconson +/- N 200km), the plant body of T. borealis persists as a tuber that lies just beneath the organic litter layer . In May, the stem begins to elongate through the litter, bringing the young expanding leaves, formed the previous fall, above the surface. Development is slightly earlier in the south during the spring, but by midsummer differences are minor. Stem elongation and leaf expansion can continue into the 1st week of June in both areas. Flowering begins when the leaves have reached about 9% of full expansion. The majority of the plants flower in May and early June; the extreme dates within the State are May 9 in the south and June 25 in the north."[Anderson]

"Rhizomes are initiated at the base of the shoot in June and continue to develop into the 2nd or 3rd week of July, but tuber formation can begin in August. Typically, each plant produces a single rhizome; however, two are not uncommon and branching occurs frequently. Of 93 plants at the northern study site, 3.2% produced no rhizomes; 61.3% produced one rhizome; 30.1% produced two; and 5.4%, three."[Anderson]

"Rhizome length seems to be closely related to plant size and habitat conditions and will vary from 5-6cm in dry sandy locations to 1 m or longer in mesic sites. In the finnerud Forest of northern Wisconsin the average length was about 30 cm."[Anderson]

"The average of all plants studied is 1.2 rhizomes per plant. During August the tuber continues to enlarge, and the storage portion reaches its maximum dimension by the end of August. At this time the shoot begins to develop on the forward end of the tuber and near the end of September immature leaves are recognizable on the shoot. Adventitious roots are initiated and anchor the tuber in the substrate. Throughout October shoot morphogenesis continues, a lengthening of the stem and continued leaf development. The connection of the rhizome from the old plant to the newly formed tuber is usually severed by the end of October."[Anderson]

"While the underground organs are actively growing during the middle and latter part of the summer, senescence (growing old) characterizes the aboveground portion. Necrotic spots and slight insect damage appear by the end of July, and the leaves begin to yellow. This deterioraton continues into August, and by September most of the leaves have fallen or are completely brown."[Anderson]


  1. [Anderson]Aspects of the Biology of Trientalis Borealis RAF., Roger C. Anderson and Orie L. Loucks, Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706
  2. [E-flora]
      • [VFBC] The Vascular Flora of British Columbia, draft 2014.
  3. [PFAF] Accessed March 22, 2015; March 24, 2021
  4. []
  5. [UMD-Eth]

Page last modified on Wednesday, March 24, 2021 9:18 PM