Contributed by: Dr. Alex Lasseigne; Dept. of Biological Sciences; Nicholls State University; Thibodaux, LA 70310. U.S. Department of Agriculture APHIS-PPQ. Noxious weeds of the Federal Noxious Weed Act, No. 26
Family Name: Fabaceae [Leguminosae]
Genus Name: Galega L., sp. Pl. 714. 1753. Type species: Galega officinalis L., Sp. Pl. 714. 1753.
One of the species, Galega officinalis, is on the list of weeds for the Federal Noxious Weed Act. The genus as a whole can be identified by having robust, much-branched stems; odd-pinnate leaves with 6-12 pairs of leaflets (+ a terminal one); many-flowered, long-pedunculate, axillary or terminal racemes; blue, lilac, or white papilionaceous flowers; more or less monadelphous stamens (filaments fused into a tube split at the top); and dehiscent, linear-cylindric, torulose legumes with slender, obliquely striate valves.
Species Name: Galega Officinalis L., Sp. Pl. 714. 1753.
Plants perennial, ascending, robust, glabrous to sparsely pubescent herbs 0.4-1.5 m tall; stems much-branched, hollow. Leaves compound (odd-pinnate), alternate, petiolate; stipules herbaceous, 1/2 sagittate, extending 6-10 mm above and 3-5 mm below the point of attachment; leaflets 4-10 pairs + a terminal leaflet, oblong, elliptic, lanceolate, or ovate-oblong, 15-50 mm long X 4-15 mm broad, margins entire, apices mostly acute, rarely obtuse, mucronate or emarginate, bases mostly cuneate. Inflorescence a 30- to 50-flowered, pedunculate, axillary or terminal receme; peduncle as long as or longer than the subtending leaf, 7-10 cm in flower, elongating in fruit; bracts persistent, linear-subulate, 3-5 mm long; bracteoles absent. Flowers zygomorphic, perfect; calyx tubular-campanulate, gibbous at base on upper side, glabrous to sparsely pubescent, with 5 linear to setaceous, subequal teeth 2-3 mm long (ca. as long as the tube); corolla white, lilac, or purple, papilionaceous, 10-15 mm long, the petals subequal (standard obovate-oblong, narrowed below into a short claw; wings oblong, slightly joined to the blunt, subobtuse keel); stamens 10, more or less monadelphous (filaments fused into a 3-6 mm long tube split at the top), the anthers small, uniform or alternately longer and smaller, elliptic, dorsifixed; ovary sessile, many-ovuled, the style incurved, the stigma small terminal. Legume semierect, linear-cylindric, 20-50 mm long X 2-3 mm wide, torulose, tipped by the remnant style, dehiscent, 2-valved, the valves slender, obliquely striate, continuous within, sometimes constricted between the seeds; seeds 2-10, transversely oblong with raised lens and micropylar region and with an oblique furrow on each face near the lens, 3-4.5 mm long X 1-1.5 mm in diameter, reddish-brown to dark brown, with the embryo clearly apparent.
Source: Brooks s.n., Utah (US).
Goatsrue is now considered to be a deep rooted, long-lived perennial weed which propagates by seeds. In Chile, it is regarded as a serious weed in humid grasslands, where it may completely cover fields. The plant was introduced into Utah in 1891 for testing as a forage, where it presumably escaped and now occupies about 60 square miles in Cache Co. Within this area it infests cropland, fencelines, pastures, roadsides, water-ways, and wet, marshy areas (Evans and Ashcroft 1982).
Galega officinalis contains a poisonous alkaloid, galegin. The plants have a bitter taste and are unpalatable to cattle and horses. The common name, goat's rue, indicates its toxicity for goats, causing vomiting and even death under some conditions (Allen and Allen 1981).
Tingey (1971) listed several methods of controlling goatsrue, including the use of herbicides; cropping, cultivation, and crop rotation on tillable land; and mowing in patures. But, Evans and Ashcroft (1982) stated that "mowing, clipping, cutting, and shallow cultivation are poor means of control, as the plant will flower and produce seed even when very small."
Tingey (1971) reported that the growth habit of goatsrue is similar to that of alfalfa, but unlike alfalfa, the pods are narrow, straight, round in cross section, and about 1-inch long. They also stated that the seeds resemble those of alfalfa, but are much larger.
Wild licorice (Glycyrrhiza lepidota) may be confused with goatsreu, but wild licorice has solid stems [vs. hollow ones], and stipule lobes only above the point of insertion [vs. 1/2 sagittate], and the pods are burlike with hooked bristles [vs. linear-cylindric and smooth] (USDA-APHIS mimeo, w/o date).
Chamberlain (1970) stated that variants [of goatsrue] with dark purple standards and pale wings and standards [?keel] have sometimes been treated as separate species, G. patula Stev. or G. bicolor Hausskn. These names are now usually listed in synonymy under Galega officinalis.
Bailey, L.H. and E.Z. Bailey. 1976. Hortus third: A concise dictionary of plants cultivated in the United States and Canada. Macmillan Publ. Co., New York. 1290 pp.
Chamberlain, D.F. 1970. Galega. In P.H. Davis (ed.), Flora of Turkey 3:41-42.
Clapham, A.R., T.G. Tutin, and E.F. Warburg. 1962. Flora of the British Isles. 2d ed. University Press, Cambridge.
Evans, J.O. and M.L. Ashcroft. 1982. Goatsrue. Utah Agr. Exp. Stat. Res. Report 79. 5 pp.
Tingey, D.C. 1971. Goatsrue, a potential forage crop, turned out to be a weed. Utah Sci. 32(1):25-28.
Willis, J.C. 1980. A dictionary of the flowering plants and ferns. 8th ed. University Press, Cambridge. 1245 pp + appendix (1xvi pp).
|Bargeron, C.T., D.J. Moorhead, G.K. Douce, R.C. Reardon & A.E. Miller |
(Tech. Coordinators). 2003. Invasive Plants of the Eastern U.S.:
Identification and Control. USDA Forest Service - Forest Health
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