Lomatogonium rotatum (L.) Fr. ex Fernald
Marsh Felwort.
Gentianaceae, gentian family.
Rhodora 21: 194. 1919
Swertia rotata L., Sp. Pl. 226. 1753
Vegetative morphology. Plants dwarf shrubs, or low shrubs; 5–10(–30) cm high (on Continental North America); small, purplish-green, with single branched or unbranched stems. Taproot present (poorly developed). Roots yellow. Aerial stems erect; glabrous. Leaves distributed along the stems, or basal in a rosette; opposite. Petioles absent. Leaf blade bases truncate. Blades 5–20 mm long; 1–3 mm wide. Blades spreading; lanceolate, or spatulate (basal leaves), or linear (-lanceolate, stem leaves); flat; with inconspicuous veins. Blades adaxial surface glabrous. Blades abaxial surface glabrous. Blade margins entire. Leaf apices obtuse.
Reproductive morphology. Flowering stems present. Flowering stems conspicuously taller than the leaves; with leaves; glabrous. Flowers solitary, or in inflorescences (terminal single flowers lateral branches). Inflorescence cymose (if applicable). Flowers medium-sized, 5–15 mm in diameter or length (continental North America). Calyx sepals 4, or 5; fused (only near the base; essentially free); 5–15 mm long (0.5–1.5 mm wide). Calyx green (linear-lanceolate, acute); rotate; 4-lobed, or 5-lobed (or 6, see image library); glabrous. Petals fused (at the base only); 4, or 5(–6); blue, or white (rarely); 5–10 mm long. Corolla rotate (the tube very short, not folded: each lobe bearing several fringed scales at the base); 4-lobed, or 5-lobed (the lobes ovate to pointed). Stamens 4, or 5; fused to the corolla (at the base); filaments glabrous (flattened). Anthers blue; stout-cylindrical; 0.4–0.6 mm long. Nectaries present (at the base of the corolla tube alternate with the stamens). Gynoecia superior. Carpels syncarpous; 2. Ovaries oblong; glabrous. Placentation parietal. Ovules 100 (numerous). Fruit with calyx persisting; dry; a capsule; ellipsoid (the valves strongly recurved at the tip); dehiscent. Fruit 10–15 mm long (exserted from the marcescent and closed corolla); 3–4 mm wide; yellowish, or brown; glabrous. Seeds 0.5–0.75 mm long (longer than wide); brown; with surfaces smooth (slight texture seen at 40X).
Chromosome information. 2n = 10 and 16. (2x, x =
5?). - D.Löve (1953 Iceland); Löve and Löve (1956b
Iceland, 1982a arct Canada).
16 (2x, x = 8?). -
Löve and Löve (1986); Yuan and Küpfer (1993 China). Supposed
basic chromosome number of family 2x.
Distribution. Northern hemisphere distribution: circumpolar (nearly); Greenland, Canada, United States, Eurasia. Low arctic. Range in the Canadian Arctic Archipelago limited. Rare. Arctic Islands: Victoria.
Ecology and habitat. Substrates: imperfectly drained moist areas; with high organic content.
Illustrations. • Plant habitat. Plants with single pale blue flowers, near the markers, growing above high tide line in a coastal grassy meadow. First year plants small; second year plants much larger. Manitoba, Churchill, Beech Cove. Aiken and Brysting 01–023a. CAN. • Plant habit. Plants with blue flowers behind the markers growing above high tide line in a coastal grassy meadow. Manitoba, Churchill, Beech Cove. Aiken and Brysting 01–023a. CAN. • Plant habitat. Plants with blue star-like flowers, near the pencil growing along a stream bank, above high tide line in a coastal grassy meadow. Manitoba, Churchill, Beech Cove. Aiken and Brysting 01–023a. CAN. • Plant habitat. Plants, less than 10 cm high, growing in a marshy area among Carex aqualtilis. N.W.T. Tuktoyaktuk. Aiken and Brysting 01–114. CAN. Scale bar in cm. • Close-up of plants. Plants 30–40 cm high with pale blue flowers, beside the markers. Manitoba, Churchill, Beech Cove. Aiken and Brysting 01–023a. CAN. • Close-up of plants. Plants much less than 10 cm high visible as single blue star-like blue flower, one with four and one five petals. Aiken and Brysting 01–114. CAN. • Close-up of flowers. Flower with 6 linear, green, calyx segments, 6 free blue petals with prominent insect guide liines, and 5 anthers. Manitoba, Churchill, Beech Cove. Aiken and Brysting 01–023a. CAN. • Close-up of 4-merous flower. Flower with 4 purple-blue petals, 3 stamens with dehisced anthers that are shedding pollen and a developing gynoecium at the base of which are the tips of white fringing on the top of the nectaries. Aiken and Brysting 01–023a. CAN. • Close-up of 5-merous flower. Post-anthesis flower with insect crawling on one of 5 linear sepals, 5 purple-blue petals, and anthers no longer present, Necatries near the gynoecium have a white fringe on top. Top of gynoecium is dividing into two styles. Aiken and Brysting 01–023a. CAN. • Black and white plate. a=plant, actual height approximately 25 cm high. b=rotate corolla showing pointed tips to the petals and anthers attached at the base of the petals. c=calyx with sepals essentially free. D=seed. Plate from Gillett (1963) with permission. • Arctic Island distribution.
Cite this publication as: ‘S.G. Aiken, M.J. Dallwitz, L.L. Consaul, C.L. McJannet, L.J. Gillespie, R.L. Boles, G.W. Argus, J.M. Gillett, P.J. Scott, R. Elven, M.C. LeBlanc, A.K. Brysting and H. Solstad. 1999 onwards. Flora of the Canadian Arctic Archipelago: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 29th April 2003. http://www.mun.ca/biology/delta/arcticf/’. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).
