Lomatogonium rotatum (L.) Fr. ex Nyman:
Canada (North America)
Greenland (North America)
Japan (Asia)
Kazakhstan (Asia)
Mongolia (Asia)
Russian Federation (Asia)
United States (North America)
China (Asia)

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Greenland to Alaska, south to Colorado.

Annuals 15-40 cm tall. Stems erect, angular, much branched; branches crowded, glabrous. Leaves sessile, linear to broadly lanceolate, 1.5-4.3 × 0.2-0.4 cm, base obtuse, apex acuminate, midvein abaxially and adaxially distinct. Inflorescences racemelike, usually in many-flowered panicles. Flowers 5merous. Pedicel spreading to erect, to 8 cm, angular, glabrous. Calyx tube 1-1.5 mm; lobes linear to linear-lanceolate, 0.8-2.2(-2.7) cm, apex acuminate, midvein distinct. Corolla pale blue, with dark blue lines, 2-3 cm in diam., tube 1-1.5 mm; lobes elliptic-lanceolate to elliptic, 1.5-2.5 cm, apex acuminate to obtuse. Nectary connate at base into a tube pointed outward, apex lamellate, margin lobed. Filaments 6-8 mm; anthers blue, narrowly ellipsoid, 3-4.5 mm. Ovary ensiform to obconic, 1.2-1.4 cm, apex triangular acute. Stigma lobes triangular, decurrent to base of ovary. Capsules narrowly ellipsoid to obovoid-ellipsoid, 1.5-2.5 cm. Seeds light brown, globose, 0.3-0.4 mm in diam.; seed coat smooth. Fl. and fr. Aug-Sep.

Swertia perennis has similar flowers but is a perennial. Annual gentians have tubular rather than star-shaped corollas. This plant is often overlooked because it blooms in August.

Comments: The more salient features of the habitat of Lomatogonium rotatum include moist soils, full sunlight, minimal competition, and, in eastern North America, close proximity to the sea along outer islands and headlands. Hence it most characteristically grows in thin soils bordering headlands or ledges or in pockets of sandy or gravelly soil. A soil test from Red Head on Great Wass Island, performed by the Maine Soil Testing Lab, indicates circumneutral pH and an excessive level of calcium. It is frequently found in seepage areas between boulders and in turf surrounding temporary and permanent brackish and freshwater pools, and in moist rock crevices. It generally does not colonize crevices close to the breaking surf.

Associated species of Lomatogonium rotatum in Maine include: Agrostis stolonifera, Aster novi-belgii, A. NEMORALIS, Campanula rotundifolia, Carex canescens, C. VIRIDULA, Deschampsia flexuosa, Empetrum nigrum, Euphrasia canadensis, E. RANDII, Festuca rubra, Iris hookeri, Juncus filiformis, Plantago juncoides VAR. DECIPIENS, Prenanthes trifoliata, Primula laurentiana, Sagina nodosa SSP. BOREALIS, Solidago bicolor, Triglochin maritima, and Viola septentrionalis.

1100-4200 m. Gansu, Guizhou, Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Yunnan [Japan, Kazakhstan, Mongolia, Russia; Europe, North America]

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 6 - 20

Comments: No clear estimates of its population level are known. It has been recorded (Table 1) on 8 islands in the Great Wass Island Archipelago plus one island off Schoodic Point (Little Moose Island) (Olday et al. 1982) and on Schoodic Point itself (Stebbins 1928). There are at least three distinct populations on Great Wass Island, three on Outer Sand Island, and five on Inner Water Island. Table 1 gives the names of all current and historic locations for Lomatogonium in Maine. All of these locations have extant populations except for Schoodic Point, and were visited in 1982 (two islands) and 1983 (seven islands).

Lomatogonium rotatum's distribution in Maine is restricted to the moist maritime zone along the coast of eastern Maine (Famous and Campbell in prep). Compared to inland and coastal sections farther west summer temperatures are cooler, the incidence of fog is higher, rainfall and fog-drip rates are higher, and evaporation rates are lower, providing an abundance of water. These conditions are not as extreme when Lomatogonium rotatum is in full bloom in August and September.

Little is known about the reproductive biology of this species. Floristic manuals indicate that this is an annual or biennial. Longer term studies are needed to determine its duration. The pollinators are unknown. Syrphid flies, bumblebees, and several species of butterflies are present in or near their populations, and a syrphid fly was seen visiting Lomatogonium in late September on Water Island (Inner Water Island). It is likely that nectar is the reward for pollinators, although we did not verify the presence of nectar. It appears that this species is reproducing succesfully by seed. Many reproductively mature plants were observed as well as reproductively immature, non-flowering individuals. It is also unknown how the seeds are dispersed. Because of its short stature migratory songbirds, esp. Fringillids, may be involved with seed dispersal and/or seed predation.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Species: 8
Species With Barcodes: 1

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N4 - Apparently Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread and locally abundant circumboreal species, rare at southern edges of range (e.g., Maine).

Comments: Lomatogonium rotatum grows where hikers, beachcombers, and nature lovers are likely to walk. At this time, other threats such as animal predation, loss of habitat through succession, or displacement by other plants do not appear to be important to Lomatogonium on Great Wass Island, Crumple Is. and Mistake Is. (all in ME; TNC owned islands). It is unlikely that these factors are adversely affecting the other known Lomatogonium locations. The population at Schoodic Point, ME, whose status is unknown, would be the most susceptible to trampling or picking as it is (was?) located in a high use area of Acadia National Park.

Restoration Potential: Not enough is known about germination requirements or the soil needs of seedlings to predict how population size would respond to soil changes associated with human trampling.

Preserve Selection and Design Considerations: The Nature Conservancy might prevent the building of trails to certain parts of Great Wass Island (e.g., the headland located on the southwest corner of the Pond or to Red Head).

Management Requirements: It is our opinion that Lomatogonium rotatum occupies vegetationally stable habitats in eastern Maine and that short-term reductions in population size are most likely to result from human activity like trampling and development.

Monitoring Programs: C.S. Campbell, N.C. Famous, C.D. Richards and B.S. Vickery know the locations of some or all of the extant sites in Maine.

Management Research Needs: (1) What is the abundance and distribution of Lomatogonium in eastern Maine? (2) How large are the effective population units? Are larger populations on larger islands a series of discrete small populations such as is seen on Great Wass Island? (3) How do plants respond to trampling? (4) How narrow is the niche of Lomatogonium rotatum or how narrowly adapted is it to limited competition and soil characteristics like pH, aeration, and organic content?

Biological Research Needs: What is the reproductive biology of this species? Who are its pollinators? Are individual plants self-compatible? Do they need pollinators to set seed? Can they reproduce vegetatively? Are there mechanisms to promote outcrossing and thereby presumably population variability? How much seed production occurs in natural populations? How are seeds dispersed? What conditions are necessary for germination?

Needs: The Nature Conservancy might prevent the building of trails to certain parts of Great Wass Island (e.g., the headland located on the southwest corner of the Pond or to Red Head).

Stewardship Overview: Studies on the distribution and abundance of Lomatogonium rotatum in eastern Maine, and its reproductive biology, and demographic studies of populations on selected locations in Maine could be very informative about the factors controlling the distribution and abundance of these species. However, in view of the apparent size and stability of the populations in eastern Maine and low level of threat, stewardship needs are minimal.