Achlys

de Candolle

Syst. Nat. 2: 35. 1821.

Etymology: Greek Achlus, a god of night
Treatment appears in FNA Volume 3.

Herbs, perennial, deciduous, 2.5-5 dm, glabrous. Rhizomes extensive, branching, producing 1-few foliage leaves or flowering shoots per year. Aerial stems absent. Leaves basal, alternate, 3-foliolate; petiole long, slender. Leaf-blade orbiculate in gross outline, 20-40 cm; leaflet blades fan-shaped, entire or lobed, lateral leaflet blades strongly asymmetric, margins entire to coarsely sinuate; venation palmate. Inflorescences terminal, dense scapose-pedunculate spikes of inconspicuous flowers. Flowers 3-merous, white to cream, 6 mm or less; bracteoles absent; sepals absent; petals absent; stamens 8-10 (-13); anthers dehiscing by 2 apically hinged flaps; pollen exine striate; ovaries asymmetrically ellipsoid; placentation marginal, placenta developed only near base of ovary. Fruits follicles with transverse dehiscence, purplish red or brown, curved, furrowed. Seeds 1, brown; aril absent. x = 6.

Distribution

North America, Asia (Japan)

Discussion

Species 3 (2 in the flora).

Achlys is of particular interest because of its amphi-Pacific disjunction. Despite the 8000 km or more disjunction, the taxa are remarkably similar in morphology, ecology, and karyology. Japanese populations are diploid; American populations are diploid and tetraploid.

Two species are recognized in this treatment; some researchers prefer to treat them as varieties. In the Californian portion of the range, some field botanists believe the two taxa are sufficiently morphologically distinct to be called species; farther north these differences are reportedly less apparent.

Selected References

None.

Key

1 Central leaflet blade 4–11 cm, distal margins (1–)3–4(–8)-lobed; stamens 3–4 mm; follicles red-purple. Achlys triphylla
1 Central leaflet blade ca. 7–16 cm, distal margins (3–)6–9(–12)-lobed; stamens 3.8–6 mm; follicles brown. Achlys californica

"less" is not a number.

... more about "Achlys"
R. David Whetstone +, T.A. Atkinson +  and Daniel D. Spaulding +
de Candolle +
20 cm200 mm <br />0.2 m <br /> (40 cm400 mm <br />0.4 m <br />) +
North America +  and Asia (Japan) +
small +  and large +
Greek Achlus, a god of night +
white;cream +
inconspicuous +
6 cm60 mm <br />0.06 m <br /> (?) +
brown +  and purplish red +
axillary +  and terminal +
3-foliolate +
entire;coarsely sinuate +
1-carpellate +
basal +  and superior +
ellipsoid +
3-merous +  and 2-merous +
distinct +
extensive +
distinct +
scapose-pedunculate +
elongating +
palmate +  and pinnate +
persistent +
Berberidaceae +
deciduous +  and perennial +