Horkelia truncata |
Horkelia marinensis |
|
---|---|---|
Ramona horkelia |
Point Reyes horkelia |
|
Habit | Plants tufted, green. | Plants matted, green to grayish. |
Stems | erect, 2–6(–8) dm, hairs spreading. |
± decumbent to ascending, 1–3.5(–4.5) dm, hairs spreading to ascending. |
Basal leaves | planar, 4–13 × 2–3.5(–4) cm; stipules entire or basally lobed; leaflets 1–3 per side, separate, oblong to obovate, 10–30 × 5–12(–15) mm, ± 1/2 as wide as long, divided 1/6–1/4 to midrib into (15–)20–30 acute to obtuse teeth, sparsely short-pilose to glabrate, especially adaxially. |
± planar to nearly cylindric, 4–12(–15) × 1–2.5(–3) cm; stipules entire or basally lobed; leaflets 5–10(–12) per side, ± overlapping especially distally, cuneate, 7–12 × 5–10 mm, nearly as wide as long, divided 1/3–1/2 to midrib into (3–)5–10 acute to obtuse teeth, villous. |
Cauline leaves | 4–7. |
3–5. |
Inflorescences | open, flowers arranged individually. |
usually congested, flowers usually arranged in dense corymbiform clusters. |
Pedicels | 4–20(–30) mm. |
1–6 mm. |
Flowers | 12–17 mm diam.; epicalyx bractlets broadly ovate, 3–4.5 × 2–3 mm, ± 2/3 length of sepals, entire; hypanthium 1.5–2 × 5–8 mm, less than 1/2 as deep as wide, interior glabrous; sepals ± reflexed, broadly ovate, 3.5–5.5 mm; petals obovate to round, 5–7 × (3–)4–7 mm, apex ± rounded; filaments 1–2 × 0.5–2 mm, anthers 0.8–1 mm; carpels 50–80; styles 1.5–3 mm. |
10–15 mm diam.; epicalyx bractlets lanceolate, 2.5–4.5 × 1 mm, ± 2/3 length of sepals, entire; hypanthium 1.2–1.5 × 4–5 mm, less than 1/2 as deep as wide, interior pilose; sepals ± reflexed, lanceolate, 3–6 mm; petals narrowly oblanceolate to narrowly oblong, 4–7 × 2 mm, apex obtuse to rounded, rarely truncate; filaments 1–2.8 × 0.2–0.6 mm, anthers 0.6–0.9 mm; carpels 20–30; styles 2–4 mm. |
Achenes | brown, 1.3–1.5 mm, smooth. |
brown, 1.5–2 mm, smooth to slightly rugose. |
2n | = 56. |
|
Horkelia truncata |
Horkelia marinensis |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Dry clay soil, in chaparral communities, oak woodlands | Sandy coastal flats, stabilized dunes |
Elevation | 400–1300 m (1300–4300 ft) | 0–800 m (0–2600 ft) |
Distribution |
CA; Mexico (Baja California)
|
CA
|
Discussion | Of conservation concern. Horkelia truncata is confined to the Peninsular Ranges of San Diego County, California, and northern Baja California, Mexico. Plants of the species are unusual in Horkelia in that the terminal leaflet is usually notably larger than the lateral leaflets, unlobed, and distinct, rather than confluent with the distal lateral ones. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Horkelia marinensis occurs in three population clusters along the coast of California: near Fort Bragg and Rockport in Mendocino County, on Point Reyes Peninsula in Marin County, and from Santa Cruz and (historically) San Mateo counties. The last population cluster has often been confused with H. cuneata var. sericea; plants of it have more deeply and apically toothed, cuneate leaflets and longer, silkier hairs. It is also the basis for the attribution by J. H. Thomas (1961) of H. rydbergii (as H. bolanderi subsp. parryi) to the Santa Cruz Mountains. The three population clusters differ somewhat in vestiture, evident glandularity, and leaflet shape and size; further studies may indicate that varietal status is justified. References to H. marinensis in Sonoma County (M. G. Barbour 1970) are based on specimens of Acaena pinnatifida var. californica; reports from southern Mendocino County (G. L. Smith and C. R. Wheeler 1990–1991) are based on misidentifications of H. californica and H. tenuiloba. Horkelia marinensis is by far the most aromatic member of the genus; the odor, which has been compared to that of a beehive, often can be perceived even before the plants are located, especially on sunny days. Plants do relatively well in cultivation, forming spreading mats with flowers that are strongly attractive to both native bees and honeybees. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 9, p. 256. | FNA vol. 9, p. 253. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Potentilla truncata | H. bolanderi var. marinensis, Potentilla kelloggii var. marinensis, P. marinensis |
Name authority | Rydberg: in N. L. Britton et al., N. Amer. Fl. 22: 274. (1908) | (Elmer) Crum: Lloydia 1: 91. (1939) |
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