Menonvillea rigida Rollins (1955: 14)
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publication ID |
https://doi.org/ 10.11646/phytotaxa.162.5.1 |
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persistent identifier |
https://treatment.plazi.org/id/03EF87C8-014C-A447-0297-FC7EFC73FA30 |
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treatment provided by |
Felipe |
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scientific name |
Menonvillea rigida Rollins (1955: 14) |
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8. Menonvillea rigida Rollins (1955: 14) View in CoL . Type:— ARGENTINA. [Provincia de Neuquén]. Arroyo Manzana, Andes Expedition 38– 41°S, 1925−1927, H . F . Comber 1130 (holotype K!; isotype GH! fragm. ex K) .
Perennials with thick, deep, fleshy to woody, branched caudex. Stems (6−)9−25(−30) cm, fleshy or more frequently woody, thick, erect, generally unbranched above, with numerous leaf scars, pubescent to canescent with simple, terete, straight, retrorse or less frequently spreading to antrorse trichomes 0.5−1.2 mm long. Leaves cauline, subsessile, cuneate, 7−18(−25) × (3−) 5−8 mm, canescent, generally with retrorse trichomes or sometimes antrorse to spreading adaxially, base cuneate to attenuate, margin entire, apex 3-lobed or 3-dentate. Racemes terminal, ebracteate or frequently bracteate proximally, corymbose, densely flowered, slightly elongated in fruit, 3− 6 cm long; rachis straight, canescent; fruiting pedicels ascending to divaricate or reflexed, straight to recurved, (6−) 8−14 mm long, densely pubescent with spreading trichomes. Sepals oblong, 4−6 × 2−2.5 mm, pubescent, erect, not saccate, caducous, margin scarious; petals white, spatulate to broadly so, 6.5−9 × 1.5−3.5 mm, clawed, not papillate at base; stamens tetradynamous; filaments free, erect, dilated and not papillate at base, 3−5.5 mm long; anthers narrowly oblong, 1.2−2 mm long; nectar glands confluent, ringlike, subtending bases of all filaments. Fruits subglobose, pubescent with spreading trichomes; valves 3-winged, conspicuously veined, 9−13(14) × 7−12 mm, emarginate apically, wings 1.5−2(−2.7) mm wide; gynophore 1.5−2(−3) mm long; style 2−3 mm long; stigma slightly decurrent. Seeds ovate, ca. 4 × 3 mm, wingless, flattened; cotyledons accumbent.
Distribution and habitat:— Menonvillea rigida is endemic to Argentina where it grows in north-central Patagonia (Neuquén and Río Negro) on rocky slopes at elevations of 1500−1900 m ( Fig. 12H View FIGURE 12 ).
Phenology:— Flowers from December to March.
Taxonomic notes:— Although Rollins (1955) considered Menonvillea rigida to be morphologically related to M. nordenskjoeldii , the species also seems to be related to M. cuneata , as both have simple, terete, straight and usually retrorse trichomes 0.5−1(−1.2) mm long, compared to trichomes 1−2(3) mm long in M. nordenskjoeldii . Furthermore, their leaves are 3-dentate to slightly 3-lobed, whereas those of M. nordenskjoeldii are deeply 3−5(− 7)-lobed at apex. Based on these similarities, Al-Shehbaz (2008) included M. rigida in the synonymy of M. cuneata . However, the former has thick and conspicuously woody stems with numerous leaf scars and fruit valves 9−13(−14) mm long. By contrast, M. cuneata has generally thin, fleshy or slightly woody stems without leaf scars, and the fruit valves are (4−)5−8(−11) mm long. Also, leaves of M. rigida have trichomes antrorse adaxially and retrorse to spreading abaxially [as in Diem 933 (LIL, SI), Diem 2959 (BAB), Neumeyer 596 (SI)], whereas those of M. cuneata have retrorse to spreading trichomes on both surfaces. Molecular phylogenies agree with Rollins (1955) in recognizing M. rigida as most closely related to M. nordenskjoeldii .
Representative Specimens:— ARGENTINA. Neuquén: Depto. Huiliches, Parque Nac. Lanín , ladera N, subiendo al refugio por sendero de mulas, 1 February 2000, Ezcurra 2979 ( BCRU) ; Depto. Lácar, Cerro Chapelco , 11 December 1963, Schajovskoy 7712 ( BAB) ; Depto. Los Lagos, Filo Machete al Cerro Rothkugel , 11 March 1945, Diem 933 ( LIL, SI) ; Villa Puerto Manzano , 11 February 1962, Diem 2959 ( BAB) . Río Negro: Depto. Bariloche, cerro Capilla , faldeo Sur , March 1942, Neumeyer 596 ( SI) .
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