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alpine meadow-rue, arctic meadow-rue, dwarf meadow-rue, pigamon alpin

southern meadow-rue

Roots

brownish, fusiform-tuberous with dried ribs.

Stems

erect, scapose, or nearly scapose with very slender rhizomes, (3-)5-20(-30) cm, glabrous.

reclining, branched and flexible proximally, 10-40 cm, glabrous.

Leaves

blade 2x-pinnately compound, proximal primary divisions ternate;

leaflets cuneate-obovate to orbiculate, apically 3-5-lobed, 2-10 mm, surfaces glabrous.

blade: leaflets ovate or obovate to reniform or orbiculate, apically shallowly to deeply 3-7-lobed, rarely undivided, 4-15 mm wide, surfaces glabrous.

Inflorescences

racemes, usually elongate, few flowered.

terminal and axillary, panicles, elongate, few flowered.

Flowers

pedicels recurved in fruit;

sepals early deciduous, purplish tinged, ovate or elliptic, 1-2.3(-2.7) mm;

stamens 8-15;

filaments purple;

anthers bright yellow, 1.5-3 mm;

stigmas purple.

sepals whitish, lanceolate to obovate, 1.5-2.7 mm;

filaments colored, not white, 1.5-2 mm;

anthers 1.7-2.5 mm, mucronate;

stigma color unknown.

Achenes

2-6, nearly sessile;

body lance-obovoid, 2-3.5 mm, with thick veins.

1-6, not reflexed, nearly sessile;

stipe 0.1-0.3 mm;

body oblong to elliptic-lanceolate, not compressed, 3-3.7 × 0.7-1.2 mm, glabrous, prominently 6-8-veined, veins not anastomosing;

beak 1.3-2 mm.

2n

= 14, 21.

Thalictrum alpinum

Thalictrum debile

Phenology Flowering late spring–summer (Jun–Aug). Flowering in early spring (Mar–Apr).
Habitat Wet meadows, damp rocky ledges and slopes, and cold (often calcareous) bogs in willow-sedge, lodgepole pine, and spruce-fir Rich, rocky, limestone woods, often in wet, alluvial soil
Elevation 0-3800 m (0-12500 ft) 50-300 m (200-1000 ft)
Distribution
from FNA
AK; CA; CO; ID; MT; NM; NV; OR; UT; WY; BC; NF; NT; QC; YT; Greenland; n Eurasia
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; GA; MS
[BONAP county map]
Discussion

Of conservation concern.

Thalictrum debile is closely related to T. arkansanum and T. texanum. The distinctions among the three species should be further studied.

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

Source FNA vol. 3. FNA vol. 3.
Parent taxa Ranunculaceae > Thalictrum > sect. Thalictrum Ranunculaceae > Thalictrum > sect. Heterogamia
Sibling taxa
T. amphibolum, T. arkansanum, T. clavatum, T. confine, T. cooleyi, T. coriaceum, T. dasycarpum, T. debile, T. dioicum, T. fendleri, T. heliophilum, T. macrostylum, T. minus, T. mirabile, T. occidentale, T. polycarpum, T. pubescens, T. sparsiflorum, T. texanum, T. thalictroides, T. venulosum
T. alpinum, T. amphibolum, T. arkansanum, T. clavatum, T. confine, T. cooleyi, T. coriaceum, T. dasycarpum, T. dioicum, T. fendleri, T. heliophilum, T. macrostylum, T. minus, T. mirabile, T. occidentale, T. polycarpum, T. pubescens, T. sparsiflorum, T. texanum, T. thalictroides, T. venulosum
Synonyms T. alpinum var. hebetum
Name authority Linnaeus: Sp. Pl. 1: 545. (1753) Buckley: Amer. J. Sci. Arts 45: 175. (1843)
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