Soilitary or weakly mat-forming herb with branched caudex and rooting stems, forming tussocks or small mats with a large number of short, vegetative shoots. Flowering stems 0–3 cm with 1–2 pairs of reduced stem leaves. Stem and base of calyx with minute, articulate hairs, mostly gland-tipped.
Leaves opposite, 3–8 mm, linear or very narrowly lanceolate, acute, without distinct sheaths, lamina with distinct, but not raised mid vein (i.e., ‘one-veined’), with minute, mostly one-celled, eglandular hairs. Dead leaves persist, often for several years.
Flowering shoots with a single terminal flower or two flowers (scientific name: 'biflora' = two-flowered), on pedicels 3–10 mm.
Flowers radially symmetric with (4)5 free sepals and petals. Sepals 2–3.5 × 0.7–1.5 mm, narrowly elliptic or very narrowly lanceolate, obtuse, with distinct mid vein and often two indistinct lateral veins, often with an uneven (fringed) and narrow hyaline white margin and purplish coloured apex. Petals longer than sepals, 3.5–5.5 × 1–1.5 mm, narrowly oblong, truncate or slightly emarginate at apex, white or rarely pale pink. Stamens 10. Gynoecium of 3 carpels with 3 stigmas.
Fruit a one-roomed capsule that opens apically with 3 teeth, with numerous seeds.
Sexual reproduction by seeds; very local vegetative reproduction by rooting branches. Flowers small and probably not adapted to insect pollination; self pollination assumed to prevail. The plant flowers and fruits regularly in Svalbard and regularly produces mature seeds. Seeds did not germinate in an experiment (Alsos et al. 2013) but we assume this to be abnormal.
No special adaptation to seed dispersal.
Cherleria biflora can be confused with species of Sabulina and Sagina. It differs from Sagina in having 3 styles and capsule teeth, whereas Sagina has 4–5 styles and capsule teeth. This is not always easily observed, but the shapes of buds, sepals and capsules are usually different. Whereas Sagina has nearly globular buds, short and boat-shaped sepals, and ovoid capsules, Cherleria and the related Sabulina have elongated buds, lanceolate sepals, and usually more elongated capsules.
Both Cherleria biflora and Sabulina rubella are (mostly) pubescent, whereas Sabulina rossii and S. stricta are (always) glabrous. Sabulina rubella differs from the three others by its three prominent veins in leaves and sepals; the others have at most one prominent vein. The sepals easily differentiate Sabulina rubella from Cherleria biflora; the former has acute to acuminate sepals, the latter obtuse.
Grows on moderately dry to moderately moist slopes and similar meadows, usually with snow protection (snowbeds) and stable soil with a humus layer. It often grows intermingled with other plants and mosses. The substrates are fine or coarse (silt to stones) and well-drained. Indifferent as to soil reaction (pH) but perhaps avoids the areas with the most basic soils (i.e., rare in the arctic steppe parts of Wijdefjorden).
Common in all zones and sections. Common on Spitsbergen and recorded from all major islands in the Spitsbergen group except for Bjørnøya.
The general range is circumpolar and arctic–alpine and the species is very widespread.
Cherleria biflora has for a long time been accepted as a species of the large genus Minuartia, but Nepokroeff et al. (2001, 2002) found support for Minuartia being heterogeneous and polyphyletic. Dillenberger & Kadereit (2014) divided the species previously assigned to Minuartia on several genera, of which the Svalbard species were assigned to two: Cherleria with C. biflora (see also Moore & Dillenberger 2017) and Sabulina with S. rossii, S. rubella, and S. stricta.
Alsos, I.G., Müller, E. & Eidesen, P.B. 2013. Germinating seeds or bulbils in 87 of 113 tested Arctic species indicate potential for ex situ seed bank storage. – Polar Biology 36: 819–830. Doi 10.1007/s00300-013-1307-7.
Dillenberger, M.S. & Kadereit, J.W. 2014. Maximum polyphyly: Multiple origins and delimitation with plesiomorphic characters require a new circumscription of Minuartia (Caryophyllaceae). – Taxon 63: 64–88.
Moore, A.J. & Dillenberger, M.S. 2017. A conspectus of the genus Cherleria (Minuartia s.l., Caryophyllaceae). – Willdenowia 47: 5–14.
Nepokroeff, M. et al. 2001. Origin of the Hawaiian subfam. Alsinoideae and preliminary relationships in Caryophyllaceae inferred from matK and trnL–C–F sequence data. – In: Botanical Society of America. 2001. Botany 2001 Abstracts: 130.
Nepokroeff, M. et al. 2002. Relationships within Caryophyllaceae inferred from molecular sequence data. – In: Botanical Society of America. 2002. Botany 2002 Abstracts: 105.