Smelowskia borealis |
Smelowskia johnsonii |
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false candytuft |
Johnson's false candytuft |
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Habit | Plants sometimes canescent basally; caudex usually simple, rarely branched. | Plants densely white-canescent throughout; caudex simple. |
Stems | several from base, often unbranched or branched proximally, 0.6–3(–3.5) dm, trichomes simple, to 1 mm, mixed with smaller, dendritic ones. |
several from base, unbranched or branched proximally, 0.4–1.6 dm, trichomes simple, 1–1.5 mm, mixed with smaller, dendritic ones. |
Basal leaves | petiole 0.5–3.2 cm, ciliate or not; blade obovate to ovate in outline, (terminal segments linear, oblong, or ovate), 0.7–2.5 cm × 4–14 mm, (terminal segments 0.2–1.1 cm × 1–5 mm), margins palmately (3 or) 5 (or 7)-lobed, (surfaces densely pubescent, trichomes dendritic, often mixed with larger, simple ones, to 1 mm), apex obtuse or subacute. |
petiole 0.8–1.3 cm, ciliate, trichomes simple; blade oblanceolate to spatulate, 0.8–1.8 cm × 3–7 mm, (terminal segments 0.2–0.7 cm × 1–4 mm), margins usually entire or apically 3-toothed or -lobed, rarely palmately 3-lobed, (terminal segments linear to ovate), apex obtuse (surfaces densely villous, silvery, trichomes primarily simple, 1–1.8 mm). |
Cauline leaves | shortly petiolate or sessile; blade often similar to basal, smaller distally, margins sometimes pinnatifid. |
subsessile; blade similar to basal, smaller distally, margins entire. |
Racemes | considerably elongated in fruit. |
elongated in fruit. |
Flowers | sepals (usually persistent), 2.5–3.2 mm; petals purple to lavender, suborbicular to obovate, 4–5 × 1.5–2 mm, narrowed to claw, 1.5–2.5 mm, apex rounded; anthers oblong, 0.4–0.5 mm. |
sepals 3–3.5 mm; petals lavender to purplish, suborbicular to obovate, 4–5 × 3–4 mm, narrowed to claw, ca. 2 mm, apex rounded; anthers oblong, 0.5–0.7 mm. |
Fruiting pedicels | spreading to divaricate-ascending, (secund, often curved), proximalmost bracteate, 6–15(–20) mm, pubescent, trichomes simple mixed with smaller, dendritic ones. |
ascending, (often forming less than 40˚ angle, straight), proximalmost bracteate, 11–27 mm, pubescent, trichomes primarily simple (to 1.5 mm). |
Fruits | spreading to ascending, usually oblanceolate to spatulate or linear-oblanceolate, rarely oblong-obovate, angustiseptate, (8–)12–28 × 4–8 mm, base cuneate, apex obtuse; valves each with prominent midvein and distinct lateral veins, (rarely sparsely pubescent); ovules 10–18 per ovary; style 0.1–1.1 mm. |
ascending, ellipsoid to obovoid-ellipsoid, subterete, 5–6 × 2–3 mm, base and sometimes apex cuneate; valves each with obscure midvein; ovules 4 per ovary; style 0.2–0.3 mm. |
Seeds | 1.5–2.2 × 1–1.3 mm. |
2.2–2.7 × ca. 1 mm. |
2n | = 12. |
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Smelowskia borealis |
Smelowskia johnsonii |
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Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Loose talus, metamorphic slide rock, rocky slopes, scree, shale splinters, limestone rubble, alpine ridges, barren rocks, unstable talus in alpine glacial bowl | Steep talus slopes, loose rocks, limestone rubble, talus |
Elevation | 600-1700 m (2000-5600 ft) | 0-600 m (0-2000 ft) |
Distribution |
AK; NT; YT |
AK |
Discussion | W. H. Drury Jr. and R. C. Rollins (1952) and Rollins (1993) divided Smelowskia borealis into four varieties based on the duration of sepals (persistent versus caducous), style length (less than versus greater than 0.5 mm), and density of indumentum. The various states of these three characters are present in all possible combinations, and they are not inherited in the combinations presented by these authors. Some forms of the species are densely villous and resemble S. johnsonii in their leaf indumentum and perhaps merit recognition as an infraspecific taxon (var. villosa). As delimited here, S. borealis is quite variable; more studies are needed to determine whether or not any of the four varieties merit recognition at some rank. Although numerous collections of the species were examined, none of the types was available for preparing this account. The species is easily distinguished from the remaining North American Smelowskia by having secund infructescences and distinctly angustiseptate fruits. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Smelowskia johnsonii is known only from the Bering Strait District, Alaska. It is a distinctive species resembling only superficially the villous forms of S. borealis with simple trichomes. From the latter, S. johnsonii is easily distinguished by having subterete (versus angustiseptate) fruits 2–3 (versus 4–8) mm wide, non-secund (versus secund) and straight (versus often curved) fruiting pedicels, 4 (versus 10–18) ovules per ovary, and simple or apically 3 (or 5)-toothed or -lobed (versus palmately (3 or) 5 (or 7)-lobed) basal leaf blades. It is readily distinguished from all species of the genus by having leaves densely silvery pubescent, with primarily simple trichomes 1–1.8 mm. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 673. | FNA vol. 7, p. 673. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Melanidion boreale, Acroschizocarpus kolianus, Ermania borealis, S. borealis var. jordalii, S. borealis var. koliana, S. borealis var. villosa | |
Name authority | (Greene) W. H. Drury & Rollins: Rhodora 54: 111. (1952) | G. A. Mulligan: Canad. Field-Naturalist 115: 341. (2001) |
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