Menonvillea litoralis (Barnéoud) Rollins (1955: 55)

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 : 277-279

16. Menonvillea litoralis (Barnéoud) Rollins (1955: 55) . Hexaptera litoralis Barnéoud in Gay (1846: 177). Type:— CHILE. [Región de Coquimbo]. Coquimbo, 1839, C. Gay 63 (holotype P!).

Menonvillea gayi Philippi (1856a: 610) . Type:— CHILE. [Región de Coquimbo]. Prov. Coquimbo, Arqueros, 1836, C. Gay 1036 [lectotype designated by Al-Shehbaz et al. (2011: 285), SGO 71223!; isolectotype SGO 63977!]. Rollins (1955) designated SGO 77937 as the type, but the sheet neither carries Philippi’s hand writing nor “Las Ánimas” cited in the protologue [ Al-Shehbaz, 2008].

Menonvillea arachnoidea Schulz (1928: 466) . Type:— CHILE. [Región de Coquimbo]. Fray Jorge , November 1922, E. Werdermann 1525 (holotype B!; isotype B, photo in F!) .

Annuals. Stems (3.5−)6–19(−35) cm, erect, branched or sometimes simple at base, glabrous or sparsely pubescent with arachnoid, slender, simple trichomes 0.25−0.45 mm long. Leaves not rosulate, sessile; blades of basal and lowermost cauline leaves filiform to linear, (1−) 2−6 cm × 0.5−1 mm, trifid or entire, glabrous or sparsely pubescent; upper cauline leaves entire, smaller than basal ones. Racemes terminal and axillary, ebracteate, corymbose, elongated in fruit, 3−6(−11) cm long; rachis glabrous or sparsely pubescent, straight; fruiting pedicels divaricate, straight or rarely slightly arcuate, (2−)4−8(−11) mm long, glabrous or sparsely pubescent. Sepals broadly oblong, 1.2−1.8(–2) × 1−1.2 mm, glabrous, erect, not saccate at base, caducous, margin membranous; petals white, broadly obovate, 2–3(−3.5) × 1.3−2(−2.4) mm, apex rounded, base abruptly narrowed into a short claw not papillate at base; stamens tetradynamous; filaments free, erect, not dilated or papillate at base, 1−2 mm long; anthers ovoid, 0.4−0.8 mm long; nectar glands 4, petaloid, apex blunt to acuminate. Fruits globose; valves 2- winged, 2−3.5(−4) mm in diam., with a well-developed dorsal callus varying from hemispherical with a conspicuous constriction all around, or oblong and not constricted at margin, clavate papillae between callus and wings sparse or rarely absent, midrib above and below the callus prominent or obscure; wings 0.5−1(−1.2) mm wide, entire or rarely undulate; gynophore 0.4−1.2 mm long; style 0.8−1.7 mm long; stigma slightly 2-lobed. Seeds ovate, 1.1−1.5 × 0.8−1.1 mm, compressed; cotyledons incumbent. Fig. 18 .

Distribution and habitat: — Menonvillea litoralis is endemic to Chile and grows in regions III (Atacama) and IV (Coquimbo) mainly in coastal areas between sea level and 500(−1100) m ( Fig. 13F ).

Phenology:— Flowers from August to November.

Taxonomic notes:— Rollins (1955) distinguished Menonvillea gayi from M. litoralis by having acuminate (vs. blunt) nectar glands, dorsal callus of valves with (vs. without) a marked constriction below, and crinkled (vs. smooth) valve wings. However, these characters do not correlate with each other or with geography. Plants with strongly developed, constricted, hemispherical callus, as well as others with slightly elevated and non-constricted oblong callus, can be found within the same population. Also, the shape and apex of nectar glands and the undulation of the fruit wing are unreliable characters because they can vary even on the same plant. Furthermore, M. gayi occupies the exact geographical range of M. litoralis . For these reasons, the former is reduced to synonymy of the latter.

Menonvillea litoralis is closely related morphologically to M. filifolia and M. marticorenae , from both of which it is easily distinguished by having white and broadly obovate (vs. yellow and narrowly spatulate) petals and fruit valves with entire or rarely undulate (vs. crenate to entire) wings.

Representative Specimens:— CHILE. III Atacama: Prov. Huasco, Com. Vallenar, Cuesta Pajonales, al N de La Serena , 12 October 1965, Garaventa 8005 ( BAA, CONC, SI) . IV Coquimbo: Prov. Elqui, Com. Coquimbo, entre Tongoy y Guanaqueros, 15 September 1965, Gleisner 10 ( CONC) ; Prov. Limarí, Com. Ovalle, Parque Nacional Bosque de Fray Jorge, desembocadura del Río Limarí , 26 August 1976, Zöllner 9930 ( CONC) .

Figures

FIGURE 13. Distribution of species of Menonvillea sect. Menonvillea. A, M. chilensis. B, M. constitutionis. C, M. filifolia. D, M. flexuosa. E, M. linearis. F. M. litoralis. G. M. marticorenae. H, M. minima. I, M. orbiculata. J, M. pinnatifida. K, M. purpurea.

FIGURE 18. Menonvillea litoralis (Barnéoud) Rollins. A, plant. B, flower. C, sepal. D, petal. E, stamens and ovary. F, nectar glands and ovary. G, fruit mericarp, ventral view. H, fruit mericarp, dorsal view. I, seed. J. embryo. From Montero 1838 (CONC). Scale bars: A = 1 cm; B–H= 1 mm; I–J = 500 µm.