Menonvillea comberi Sandwith (1928: 108)

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 : 261-262

2. Menonvillea comberi Sandwith (1928: 108) . Type:— ARGENTINA. [Provincia de Neuquén]. Sierra Mamuil , 40°S, 1650 m, 29 December 1926, H. F . Comber 914 (holotype K!; isotype E!) .

Menonvillea hirsuta Rollins (1955: 28) . Menonvillea scapigera (Phil.) Rollins subsp. hirsuta (Rollins) Prina (2001: 94) . Type:— Argentina. [Provincia de Río Negro]. Cerro Ventana, 20 January 1946, J. Neumeyer 664 (holotype, LIL 153769!; isotype, GH!, fragm. ex LIL 153769).

Annual herbs, rarely biennials, with a conspicuous taproot. Stems (3−) 5–11 cm, several to numerous from base, simple or branched above, erect to decumbent, sparsely to densely hirsute with white, antrorse to spreading, simple, terete trichomes 0.5−1.2 mm long. Basal leaves rosulate to subrosulate, petiolate; blade spatulate to broadly oblanceolate or cuneate, 0.7−3 × 0.4−1 cm, densely hirsute, subapically 5−7-lobed; cauline leaves similar to basal, smaller. Racemes terminal, bracteate proximally, corymbose, congested in fruit, 3−7 cm long; rachis hirsute, straight; fruiting pedicels ascending to divaricate or subhorizontal, straight, 0.4–1 cm long, densely hirsute. Sepals ovate to broadly oblong, 2.5−4.5 × ca. 2 mm, densely hirsute, erect, not saccate, persistent, margin membranous; petals white, spatulate to broadly so, 3.5−6(−7.5) × 1.5−3 mm, clawed, papillate at base; stamens tetradynamous; filaments free, erect, dilated and papillate at base, 1.5−4 mm long; anthers oblong, 0.7−1.2 mm long; nectar glands confluent, not petaloid. Fruits subglobose, basally notched; valves 2-winged, 4−5.5 × 3.5−5 mm, hirsute with short, spreading trichomes 0.2−0.5 mm long, with a conspicuous midvein dorsally; wings 0.5− 0.1 mm wide, entire, flat; gynophore 0.5−1 mm long; style 1−2 mm long; stigma decurrent, slightly 2-lobed. Seeds broadly ovate, 2−3 × 1.8−2.6 mm, wingless, compressed; cotyledons accumbent.

Distribution and habitat:— Menonvillea comberi grows in southern Argentina (Río Negro and Neuquén) and Chile (IX, Araucanía) on loose sandy and rocky soils of hills at elevations of 1000−1700 m ( Fig. 12B ).

Phenology:— Flowers between January and March.

Taxonomic notes: — Menonvillea comberi is easily distinguished by its annual habit, rosulate basal leaves subapically 5−7-lobed, papillate petals and stamen bases, and hirsute, 2-winged fruits with a conspicuously marked dorsal midvein. It shares with M. patagonica the annual habit, several stems from base, and a conspicuous taproot; the latter differs by having glabrous fruits conspicuously concave abaxially.

Rollins (1955) characterized Menonvillea hirsuta by including perennial plants with a conspicuous taproot, numerous suberect to decumbent stems, rosulate and 5−7-lobed basal leaves, and hirsute, 2-winged fruits with a conspicuous midvein. Prina (2001) reduced it to a subspecies of M. scapigera , but M. hirsuta clearly differs by the hirsute (vs. glabrous) fruits, 2- winged (vs. 3- or 5-winged) valves, shorter fruit pedicels (4−8 vs. 6−14 mm long), and free (vs. connate) median filaments. On the other hand, a critical study of types and additional specimens of M. comberi and M. hirsuta revealed that they are indistinguishable in vegetative, floral, and fruit characters. The alleged difference in habit (annual M. comberi vs. perennial M. hirsuta ) is unfounded because the types of both species have the same habit. Furthermore, molecular data ( Fig. 1 ) showed them to be closely related. Therefore, we follow Salariato & Al-Shehbaz (2012) in reducing M. hirsuta to synonymy of M. comberi .

Representative Specimens: — ARGENTINA. Río Negro: Depto. Bariloche, Parque Nac. Nahuel Huapi, Cerro Estratos, ladera Este , 25 February 1995, Ferreyra 409 ( BCRU) . CHILE. IX Araucanía: Prov. Malleco, Com. Caracautin, Paso Lolco, al pié del volcán Lonquimay , 2 February 1972, Zöllner 12024 ( BAA) .

Figures

FIGURE 1. Maximum clade credibility tree from Salariato et al. (2013) obtained the combined dataset ITS + trnL-F. Values above and below branches correspond to parsimony jackknife/maximum likelihood bootstrap values, respectively. Thick branches indicate> 0.95 Bayesian posterior probability.

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.