Thalictrum
(the old Greek name used by Dioscorides, probably derived from thallo, to grow green; alluding to the bright colour of the young sprouts). Meadow Rue. ORD. Ranunculaceae. A genus embracing about thirty species of hardy herbs, with perennial stems, nearly all inhabiting North temperate and frigid regions. Flowers green, yellow, purple, or white, often polygamous, paniculate or rarely racemose, usually small with the anthers conspicuously exserted, or rarely larger with smaller anthers; involucre and petals wanting; sepals four or five, petaloid; achenes often compressed. Leaves ternately decompound; cauline ones, when present, alternate. Among the species, three of which are included in the British Flora, there are several well deserving of a place at the back of the flower border. A representative selection of the most desirable kinds is presented below. Any fairly good garden soil is suitable. The plants may be multiplied by divisions.
T. alpinum (alpine). fl. few; sepals four, purplish; raceme drooping, afterwards erect, simple. July and August. l. biternate; leaflets 1/6in. to 1/4in. long, sub-orbicular, glaucous beneath, obtusely lobulate. Stem 4in. to 10in. long. often stoloniferous. Europe (Britain), Asia, and North America. (B. M. 2237; Sy. En. B. 2.) T. anemonoides (Anemone-like).* Rue Anemone. fl. several in an umbel; sepals five to ten, white, rarely pinkish, oval, 1/2in. long. Early spring. l. bi--or triternately compound; leaflets roundish, cordate at base, long-petiolulate. Stem arising from a cluster of thickened, tuberous roots. h. 6in. North America, 1768. (I. H. 1829, 211; S. B. F. G. ser. ii. 150; B. M. 866 and L. B. C. 964, under name of Anemone thalictroides.) T. a. flore-pleno (double-flowered). This only differs from the type in having double flowers. (F. d. S. 1155; L. B. C. 770.) T. aquilegifolium (Columbine-leaved).* Feathered or Tufted Columbine. fl. disposed in a corymbose panicle; sepals white, fugacious; stamens usually purple, sometimes white. May to July. l. tripinnate; leaflets sub-orbicular, smooth, deeply toothed; stipules ovate, twin. Stem fistular, purple, mealy. h. 1ft. to 3ft. Europe and Asia, 1731. (B. M. 1818; J. F. A. 318.) T. a. atropurpureum (dark purple).* Stamens and stems dark purple. T. a. formosum (beautiful). Stamens dark purple, dilated at apex. (B. M. 2025.) T. a. roseum (rosy). fl., sepals rose-coloured. 1880. T. flavum (yellow).* False Rhubarb; Fen Rue, &c. fl. often umbellate, erect, crowded; sepals pale yellow, small; anthers bright yellow; panicle compound, sub-corymbose or pyramidal. July and August. l. ternately bi-or tripinnate; leaflets 1in. to 1 1/2in. long, three-lobed. Stem 2ft. to 4ft. high, stout. Rootstock yellow, creeping. Europe (Britain) and Asia. See Fig. 21. (Sy. En. B. 8.) T. glaucum (glaucous). fl. crowded in an erect, compound panicle; sepals four or five, yellow. June and July. l., leaflets ovate-orbicular, three-lobed; lobes deeply toothed. Stem erect, round, striated, mealy. h. 2ft. to 5ft. South Europe, 1798.
T. minus (lesser).* fl. yellow, green, drooping, in lax panicles. Summer. l. triangular, three or four-pinnate; leaflets variable, acute or obtusely-lobed, often glaucous. Northern hemisphere (Britain). (Sy. En. B. 3.) Some of the forms of this species make desirable border or pot plants on account of their beautiful Maidenhair-like foliage.
T. petaloideum (petaloid-sepaled). fl. corymbose; sepals white, nearly round; filaments flesh-coloured; anthers yellow. June and July. l. ternately decompound; leaflets smooth, ovate, obtuse, entire or three-lobed. Stem round, almost naked. h. 1/2ft. Dahuria, 1799. (L. B. C. 891.) T. tuberosum (tuberous-rooted).* fl. loosely corymbose; sepals five, white, oval, blunt. June. l. crowded, petiolate, bit-tripinnate; leaflets orbicular, three-lobed, smooth. Root grumose. h. 1ft. Spain, 1713.