Galactia glaucescens Kunth (1823: 431)

Ceolin, Guilherme B. & Miotto, Sílvia T. S., 2013, Synopsis of the genus Galactia (Phaseoleae, Papilionoideae, Leguminosae) in Brazil, Phytotaxa 134 (1), pp. 1-26 : 7

10. Galactia glaucescens Kunth (1823: 431) . Type: — BRAZIL. Exact locality unknown, von Humboldt s.n. (holotype F 2388![photo]). ( Figs. 4B , 5B )

Galactia glaucescens Kunth var. lancifolia (Bentham) Burkart (1971: 771) . syn. nov.

Basyonim: Collaea lancifolia Bentham (1862: 150) . Type: — BRAZIL. Goiás: Gardner 3664 (holotype K!) .

Galactia glaucescens var. obtusa (Bentham) Burkart (1971: 771) . syn. nov.

Basyonim: Collaea obtusa Bentham (1837: 64) . Type: — BRAZIL. Minas Gerais: Schüch 148 (holotype K!) .

Erect subshrub; leaves pinnately trifoliolate (or rarely unifoliolate), bluish-green, glabrous; petiole absent or up to 7 mm long; inflorescences usually terminal, rarely axillary; flowers often with the outer surface of the standard petal greenish, with wine red coloured insect guides.

Selected specimen: — BRAZIL. Mato Grosso: Pontes e Lacerda , 15°38'S, 58°46'W, 19 January 2009, G. B. Ceolin 172 (ICN) .

Distribution: — Bolivia, Colombia, Ecuador, Paraguay, Venezuela and Brazil (BA, GO, MA, MG, MS, MT, RO, TO).

Habitat and ecology:—this species inhabits a wide range of biomes and environments. It generally grows near water, e.g., in riparian forests and on floodplains, although it is sometimes found in grassy or arboreal savannas, in dry grassland, anthropogenic grassland and shrubland. It is recorded at elevation of 150–1100 m, on serpentine substrate, in clay, and rocky or sandy soils.

Notes: — Burkart (1971) established the taxa G. glauscecens var. lancifolia and G. glauscecens var. obtusa , down-ranking the taxonomic status of G. lancifolia and G. obtusa . The former is recognized by its narrower leaflets and the latter because of its uni- rather than trifoliolate leaves. According to some authors ( Cron et al. 2007; Bennett et al. 2008), infraspecific taxa (subspecies and varieties) should be recognised only if they display a suite of morphological variations. Furthermore, this variation should be correlated with the area of occurrence of the taxon (geographic coherence). This is not the case in the described infraspecific taxa of G. glaucescens because only the leaflets show some degree of variation; all the other characters (mainly the reproductive ones) are constant. The occurrence of individuals with unifoliolate leaves at the base of the plant or even fully unifoliolate specimens commonly occurs within usually trifoliolate species of Galactia ; additionally, sometimes individuals of some species have leaves with 4–5 leaflets. For instance, in G. glauscecens , the specimen Coradin 2185 (CEN) bears leaves with five leaflets. Variation in foliage formula is relatively common in Galactia and is thus not considered to be sufficiently robust a character to maintain varieties within G. glauscecens . One of the vernacular names of G. glauscecens is “cascaveleira” (from Portuguese, cascavel = rattlesnake) in allusion to its use in popular medicine as a treatment against rattlesnake bites. Dal Belo et al. (2008) tested this popular knowledge and showed that ethanolic extracts of Galactia glauscescens leaves administered to mouse phrenic nerve-diaphragm preparations does indeed prevent the neuromuscular paralysis induced by rattlesnake venom.

Phenology:— Flowering and fruiting almost throughout the year.

Figures

FIGURE 4. A. Galactia eriosematoides. B. Galactia glauscecens. C. Galactia heringeri. D. Galactia cordifolia. E. Fruit of Galactia cordifolia.

FIGURE 5. A. Individual of Galactia marginalis showing the inflorescence few-flowered and shorter than the subtended leaf. B. Small population of Galactia glaucescens showing terminal inflorescence (senescent; arrow). C. Detail of Galactia eriosematoides showing the nodose aspect of the inflorescence as well as the wine red coloured insect guides on the outer surface of the standard petal. D. Two individuals of Galactia decumbens showing the inflorescence larger than subtended leaf and flowers aggregated at the apex.