Menonvillea macrocarpa (I.M. Johnst.) Rollins (1955: 12)

Salariato, Diego L., Zuloaga, Fernando O. & Al-Shehbaz, Ihsan A., 2014, A revision of the genus Menonvillea (Cremolobeae, Brassicaceae), Phytotaxa 162 (5), pp. 241-298 : 264

5. Menonvillea macrocarpa (I.M. Johnst.) Rollins (1955: 12) . Hexaptera macrocarpa Johnston (1929b: 166) . Type:— CHILE. [Región de Atacama]. Prov. Atacama, Depto. Vallenar, alluvial gravels at lower end of lake, Laguna Valeriano, 29°3′S, 69°52′W, 3,900 m, 8−10 January 1926, I. M. Johnston 6058 (holotype GH!; isotypes BAA!, fragm. ex GH, K!, US 1497694!).

Perennials with underground, woody, branched caudex annually producing aerial branches. Stems 8−22 cm, herbaceous, hirsute with spreading trichomes. Leaves cauline, subsessile; blade entire, oblong to narrowly elliptic or oblanceolate, 6−17 × 3−5 mm, hirsute with spreading or retrorse simple trichomes, base cuneate, margin entire, apex acute. Racemes terminal, ebracteate or proximaly bracteate, corymbose, elongated in fruit, 3.5−10 cm long; rachis hirsute, straight; fruiting pedicels erect to ascending, straight, 1−1.5 cm long, hirsute. Sepals oblong, 3−4 × 1.2−1.5 mm, pubescent, erect, not saccate, caducous, margin scarious; petals pale yellow, spatulate, 5−6 × 1.5−2 mm, slightly differentiated into blade and claw, not papillate at base; stamens tetradynamous; filaments free, dilated at base, not papillate, 3.5−4.5 mm long; anthers oblong, ca. 1 mm long; nectar glands confluent, subtending bases of all filaments, not petaloid. Fruits subglobose to broadly ellipsoid, pubescent; valves 3-winged, transversely veined, 9−13 × 8−11 mm, notched apically; wings 2−3.5 mm wide, membranous, undulate; gynophore 1−2 mm long, slender; style 3−5 mm long; stigma capitate, entire. Seeds 3.5−4 × ca. 2.5 mm, wingless, flattened; cotyledons accumbent.

Distribution and habitat:— Menonvillea macrocarpa is endemic to Depto. Vallenar in III (Atacama) Region of Chile and is known only from the type collection ( Fig. 12E ).

Phenology:— This species flowers in January.

Taxonomic notes:— Menonvillea macrocarpa and M. cicatricosa have entire leaves and 3-winged fruit valves. However, the former differs by the herbaceous (vs. suffruticose) habit, caducous (vs. persistent) petiolar bases, and pubescent (vs. glabrous) fruits. Also, M.cicatricosa grows in regions VI–VII of Chile and Mendoza in Argentina.

Rollins (1955) suggested a possible relationship between M. macrocarpa and M. cuneata . Both species have deep and woody caudices with annual aerial branches, spreading or retrorse simple trichomes, and pubescent, 3-winged fruit valves. However, M. macrocarpa has acute (vs. 3-dentate or 3-lobed) leaves and pale yellow (vs. white) petals. Although it was not possible to sequence this species in the molecular phylogenetic studies, morphological characters suggest its inclusion in Sect. Cuneata.

Figures

FIGURE 12. Distribution of species of Menonvillea sect. Cuneata. A, M. cicatricosa. B, M. comberi. C, M. cuneata. D, M. frigida. E, M. macrocarpa. F. M. nordenskjoeldii. G. M. patagonica. H, M. rigida. I, M. spathulata. J, M. virens.