Limnanthes alba
Limnanthes macounii
white meadowfoam
Macoun's meadow-foam
erect.
decumbent (sometimes upcurved apically).
2–10 cm;
leaflets 5–9, blade oblong, ovate, lanceolate, or linear-lanceolate, margins entire or shallowly 2-lobed to deeply 3-lobed.
1–7 cm;
leaflets 3–15, blade ovate, margins irregularly toothed to 5-lobed.
bowl- to bell-shaped;
sepals accrescent or not, lanceolate, ovate, or lanceolate-ovate, 4–8 mm;
petals white or cream (sometimes cream basally, aging or drying pink or lilac), obovate, obovate-cuneate, or obcordate, 8–16 mm, 1–1.5 times as long as wide, 1.25–2.1 times longer than sepals, apex usually emarginate, sometimes truncate;
filaments 3–6 mm;
anthers 1–2 mm;
style 2–6 mm.
bowl- to bell-shaped;
sepals (4) ovate, 3–4 mm;
petals (4) white, cuneate to obovate, 4–5 mm, apex emarginate (reflexed in fruit);
filaments 2–2.5 mm;
anthers cream, 0.3 mm;
style 3 mm.
gray or dark brown, 3–4 mm, tuberculate or not, sometimes ridged, tubercles gray or dark brown, relatively low and wide.
light brown, 3 mm, tuberculate, tubercles light brown, broadly conical.
= 10.
= 10.
Limnanthes alba
Limnanthes macounii
Subspecies 4 (4 in the flora).
Subspecies gracilis and parishii, previously in Limnanthes gracilis, are more closely related to subsp. alba than they are to each other. The genetic distance between them and other subspecies of L. alba is sufficient that an argument could be made for recognizing both parishii and gracilis as species (R. V. Kesseli, pers. comm.).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Limnanthes macounii is native on Vancouver Island and adjacent islands in British Columbia from East Sooke Park to Victoria, Inskip, Chatham, and Trial islands, to Yellow Point, Saltspring, Gabriola, and Hornby islands. It grows in seasonally moist depressions (including edges of vernal pools) in acidic soils that often have a high nutrient content. The population in California is in an agricultural field in San Mateo County; first discovered there in 1998 (E. G. Buxton 1998), it appears to be persisting. Phylogenetic analyses suggest this may be an aberrant population of L. douglasii (S. Meyers, pers. comm.)
The angular and comparatively massive tubercles of the nutlets of Limnanthes macounii, with the base equaling 1/4–1/3 the width of the nutlet, are unique in the genus (H. H. Hauptli et al. 1978). Allozyme studies by R. V. Kesseli and S. K. Jain (1984b) showed that L. macounii had alleles found in no other taxa at three loci. M. S. Plotkin (1998) concluded that L. macounii should be included in L. douglasii based on ITS analysis. Because of its unique characteristics and highly disjunct distribution, L. macounii is maintained as a species here pending further study.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Herbage sparsely to densely hairy; sepals densely hairy; petals 10.5-16 mm. | subsp. alba |
1. Herbage glabrous; sepals glabrous or sparsely hairy; petals 8-15 mm | → 2 |
2. Petals 8-10 mm, 1 times as long as wide, obovate; styles 2-3 mm; San Diego County. | subsp. parishii |
2. Petals (8-)12-15 mm, 1-1.3 times as long as wide, obcordate or obovate; styles 3-4 mm; central Sierra Nevada to southern Oregon | → 3 |
3. Leaflet blade narrowly oblong; petals cream, aging or drying lilac, obcordate, sparsely hairy (hairs long). | subsp. versicolor |
3. Leaflet blade ovate to linear-lanceolate; petals usually white, sometimes cream basally, aging or drying pink, obovate, glabrous. | subsp. gracilis |
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
BC
