Narrow Leaf Sorrel

Rumex thyrsiflorus is commonly misidentified as R. acetosa. The growth habit (stout, vertical rootstock), narrower, often undulate leaves with often slightly spreading basal lobes (however, some European specimens have the lobes of distal and middle cauline leaves curved inward), and pyramidal, usually much-branched panicle of R. thyrsiflorus are traits especially useful for field identification. In addition, the inner tepals of R. thyrsiflorus are distinctly smaller than those of R. acetosa. The southern European (Mediterranean) race of R. thyrsiflorus, characterized by narrower leaves with more spreading, almost hastate basal lobes and fruiting inner tepals less cordate at the base, is sometimes recognized as R. intermedius de Candolle [= Acetosa thyrsiflora subsp. intermedia (de Candolle) Á. Löve]. The same forms occasionally occur in North America (Á. Löve 1986).

Herbs perennial, dioecious. Taproots large, thick, with remote secondary roots. Stems erect, 40-120 cm tall, glabrous, grooved. Basal leaves oblong-lanceolate to lanceolate, base sagittate, 4-13 × 1.5-4 cm, both surfaces glabrous or veins minutely papillate, margin entire, apex acute, basal lobes acute at apex; cauline leaves small; petiole short or nearly absent; ocrea fugacious, white, membranous. Inflorescence terminal, paniculate, dense, much branched. Flowers unisexual. Pedicel slender, articulate below middle. Male flowers: outer tepals erect, small; inner tepals elliptic, ca. 2 mm. Female flowers: outer tepals reflexed in fruit; inner tepals enlarged in fruit; valves orbicular to broadly ovate, 3-4 mm in diam., with small recurved tubercles at base of valves, base truncate to cordate, margin nearly entire, apex obtuse. Achenes brown, shiny, ellipsoid, trigonous, ca. 2 mm. Fl. May-Jun, fr. Jun-Jul. 2n = 14, 15.

Plants perennial, glabrous or nearly so, with thick, vertical or oblique rootstock (reaching deep into substrate) and remote 2d-order roots. Stems usually erect, several from base, or occasionally solitary, branched in distal 1/ 2 (in inflorescence), (30-)40-100(-130) cm. Leaves: ocrea often with fringed margins; blade oblong-lanceolate to lanceolate, 3-12(-15) × 1-3(-5) cm, usually more than 4 times as long as wide, base sagittate or sometimes hastate (with acute lobes directed downward, ± parallel to petiole, or often reflexed outward), margins entire to obscurely and irregularly repand, usually crisped and undulate, occasionally flat, apex acute. Inflorescences terminal, occupying distal 3 of stem, usually dense, or interrupted in proximal part, broadly paniculate, pyramidal (1st-order branches usually repeatedly branched, with numerous 2d-order branches). Pedicels articulated near middle, filiform, 2-6(-7) mm, articulation distinct. Flowers (3-)4-8(-12) in whorls; inner tepals orbiculate, occasionally broadly ovate, 2.5-3.5(-4) × 2.5-3.5 mm, base rounded, truncate, or slightly cordate, apex obtuse; tubercles small or occasionally absent. Achenes black or dark brown, 1.5-1.8 × 0.8-1.2 mm, normally smooth. 2n = 14 (pistillate plants), 15 (staminate plants).

Heilongjiang, Jilin, Nei Mongol, Xinjiang [Kazakhstan, Mongolia, Russia, Uzbekistan; Europe, North America].

Mountain slopes, moist valleys, water sides; 500-2200 m.

Flowering late spring-early summer. Meadows, alluvial habitats, waste places, roadsides, edges of woods; 0-1400 m (in Europe); introduced; N.B., N.S., Ont., Que., Sask.; Mich.; c, e Europe; c Asia (s Siberia); introduced elsewhere.

Acetosa thyrsiflora (Fingerhuth) A. Löve & D. Löve; Rumex acetosa Linnaeus subsp. thyrsiflorus (Fingerhuth) Celakovský; R. haplorhizus Czernjaev ex Turczaninow; R. thyrsiflorus var. mandshuricus A. Baranov & B. Skvortsov.

Acetosa thyrsiflora (Fingerhuth) Á. Löve & D. Löve; Rumex acetosa Linnaeus subsp. auriculatus (Wallroth) A. Blytt & O. C. Dahl; R. acetosa var. auriculatus Wallroth; R. acetosa var. crispus (Roth) elakovský; R. acetosa var. haplorhizus (Czernjaev ex Turczaninow) Trautvetter; R. acetosa subsp. thyrsiflorus (Fingerhuth)     elakovský; R. auriculatus (Wallroth) Murbeck; R. haplorhizus Czernjaev ex Turczaninow

Rumex thyrsiflorus, also known commonly as the compact dock or thyrse sorrel, is a perennial herb, which grows in meadows and wasteland in most parts of Europe. It is somewhat similar to common sorrel (Rumex acetosa).