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anemone, false rue-anemone

dwarf false rue anemone, Siskiyou false rue anemone, Siskiyou rue-anemone, western isopyrum

Habit Herbs, perennial, from stout woody rhizomes or tuberous roots.
Stems

3-12 cm, cespitose, not rhizomatous;

roots tuberous.

Leaves

blade 2-ternately compound;

leaflets broadly ovate to cuneate-obovate, margins entire to deeply 3-notched.

abaxially glabrous;

leaflets entire or deeply 2-3-lobed, apex rounded, glandular-apiculate.

Inflorescences

terminal or axillary, 2-10-flowered cymes or racemes or flowers solitary, to 4 cm;

bracts absent.

axillary, flowers solitary;

peduncle strongly clavate.

Flowers

bisexual, radially symmetric;

sepals not persistent in fruit, 5(-9), white, occasionally tinged pinkish, plane, ovate to obovate, 3.5-15 mm;

petals absent;

stamens 9-75;

filaments filiform to clavate or narrowly triangular;

staminodes absent between stamens and pistils;

pistils [1-]2-10, simple;

ovules 2-6 per pistil;

style present.

sepals 3.5-6 × 1.4-2.5 mm;

stamens 8-15;

filaments flat, narrowly triangular, 1.9-3.2 mm.

Fruits

follicles, aggregate, sessile or stipitate, oblong or elliptic to obovate, laterally compressed, sides with a few prominent veins and transverse veinlets;

beak terminal, straight or curved, 0.5-3 mm.

Seeds

reddish brown, ovoid, smooth, rugulose, or minutely pubescent.

0.9-1.4(-1.7) mm, glabrous.

Follicles

stipitate, upright and appressed;

body oblong, 4-8(-9) mm, abruptly contracted into style beak;

beak 0.5-1.5 mm.

x

= 7.

Enemion

Enemion stipitatum

Phenology Flowering late winter–early spring.
Habitat Shaded shrubby areas, oak woodlands, and moist deciduous or mixed evergreen forests, occasionally in open pastures
Elevation 200-1500 m (700-4900 ft)
Distribution
from USDA
North America; Asia
[BONAP county map]
from FNA
CA; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Species 6 (5 in the flora).

The delimitation of taxa within tribe Isopyreae Schrödinger has been open to considerable debate. North American taxonomists tend to retain the North American species in Isopyrum Linnaeus whereas taxonomists elsewhere recognize Enemion along with a number of other segregate genera [e.g., Dichocarpum (Tamura and Kosuge) W. T. Wang and Fu D.-Z., Isopyrum in the strict sense, Leptopyrum Reichenbach, and Paraquilegia Drummond and Hutchinson] (J. R. Drummond and J. Hutchinson 1920; Fu D.-Z. 1990; M. Tamura 1984, 1993; M. Tamura and L. A. Lauener 1968).

Enemion has no petals and is regarded as the most primitive member in tribe Isopyreae (D.-Z. Fu 1990; M. Tamura 1984; M. Tamura and L. A. Lauener 1968). The other closely related genera form a transition series: Dichocarpum has peltate petals similar to the stamens; Isopyrum and Leptopyrum possess peltate petals with larger, tubular limbs and shorter claws; and Paraquilegia has nonpeltate petals that are flat and ± concave or swollen near the base and nearly sessile.

While some authors have argued that too much emphasis has been placed on petals as characters for segregating genera (e.g., J. A. Calder and R. L. Taylor 1963), Enemion is a well-defined taxon, easily distinguished from other members of tribe Isopyreae. Final decisions involving the circumscription of Enemion await molecular study involving all members of subfamily Isopyroideae Tamura.

All species of Enemion in the flora, with the exception of E. biternatum, are localized endemics of western North America from British Columbia to California.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Inflorescences terminal or axillary, well-defined 3–10-flowered cymes with small scalelike bracts; leaflets abaxially pubescent.
E. hallii
1. Inflorescences axillary, flowers solitary or loosely grouped in 2–4-flowered leafy cymes or racemes, bracts similar to distal stem leaves; leaflets abaxially glabrous.
→ 2
2. Follicles stipitate; peduncle strongly clavate; stamens fewer than 15, filaments flat, narrowly triangular.
E. stipitatum
2. Follicles sessile; peduncle not clavate; stamens more than 20, filaments filiform to club-shaped.
→ 3
3. Lobes of leaflets with shallow glandular notches at apices; sepals (10–)12.6–15(–16.8) mm; follicle bodies 11–15 mm; coastal British Columbia.
E. savilei
3. Lobes of leaflets glandular-apiculate; sepals 5.5–13.5 mm; follicle bodies 3.5–11.5 mm; California, c, e North America.
→ 4
4. Follicle body 3.5–6.5 mm, gradually contracted into style beak; beak 1.7–3 mm; seeds 2.1–2.7 mm, minutely pubescent; roots fibrous; c, e North America.
E. biternatum
4. Follicle body (7.7–)8.5–11.5mm, abruptly contracted into style beak; beak 0.8–1.7mm; seeds 1.5–2mm, glabrous; roots tuberous; c, s California.
E. occidentale
Source FNA vol. 3. Author: Bruce A. Ford. FNA vol. 3.
Parent taxa Ranunculaceae Ranunculaceae > Enemion
Sibling taxa
E. biternatum, E. hallii, E. occidentale, E. savilei
Subordinate taxa
E. biternatum, E. hallii, E. occidentale, E. savilei, E. stipitatum
Synonyms Isopyrum stipitatum
Name authority Rafinesque: J. Phys. Chim. Hist. Nat. Arts 91: 70. (1820) (A. Gray) J. R. Drummond & Hutchinson: Bull. Misc. Inform. Kew 1920: 160. (1920)
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