Curarea iquitana (Diels) R.Ortiz, 2018

Ortiz, Rosa del C., 2018, A taxonomic revision of Curarea Barneby & Krukoff (Menispermaceae), PhytoKeys 100, pp. 9-89 : 38-42

6. Curarea iquitana (Diels) R.Ortiz comb. nov. Fig. 20

Chondrodendron iquitanum Diels, in Mildbr., Notizbl. Bot. Gart. Berlin 9: 997. 1926. Type: Peru. "Oberes Marañon-Gebit. Mündung des Santiago", 160 m, [3] Oct 1924, (♂ fl), Tessmann 4196 (lectotype designation effected by Krukoff and Moldenke 1938, pg. 24: B!, photographs at MO!, NY!; isolectotypes: G! [G (2), F neg. 27514], NY! [NY00008329, frag.]).

Description.

Medium-sized understory lianas, (0.5-)2-7 m tall; older stems more or less terete, up to 1.5 cm diameter, bark dark brown, with shallow lengthwise fissures and scarcely tuberculate-lenticellate; branchlets glabrescent. Leaves: blades (11-)14-37 × (5-)14 -30 cm; ovate to broadly ovate; chartaceous when mature or when exposed to direct sunlight, base obtuse, truncate or weakly cordate, apex acute, acuminate, to cuspidate; surfaces discolorous, lustrous and glabrous adaxially, finely silvery tomentellous abaxially, indumentum concealing the surface at all stages, 3-5 palmati- to shortly plinerved, innermost pair of main veins acrodromous imperfect at all stages, midrib and lateral nerves slightly raised to weakly sunken adaxially, conspicuously raised abaxially, secondary veins 3(4) pairs, arising above the middle of the blade, veinlets raised above and below; petioles (3.9-)12-29.2 cm long, ridged, brownish-greyish strigillose to glabrate, apical pulvinus conspicuous, rugulose, scarcely flattened adaxially. Staminate inflorescences solitary or fascicled, axillary or cauliflorous, thyrsi, brownish to silvery strigillose, indumentum adpressed; axes (2.2-)7-14 cm long; primary branches 1-6 cm long, with (1)4-5 orders of branching; bracts (0.2-)0.7-1.2 mm long, ovate, concave, ascending, fleshy, glabrous adaxially, brown villous tomentellous abaxially. Pistillate inflorescences basically a thyrse, sometimes the primary branches reduced to single flowers, hence appearing racemose, brownish to silvery strigillose; axes 0.6-3.8 cm long; bracts 0.6-1 mm long, ovate, rather fleshy, glabrous adaxially, brownish villous abaxially. Staminate flowers 1.3-1.8 mm long, whitish, greenish, green-yellowish or orangish; pedicels (0.6-)1.3-3.1 mm long, terete, relatively thick, indumentum as on the axis, but somewhat spreading; bracteoles 2-3, 0.23-0.4 mm long, ovate or oblong, fleshy, glabrous adaxially greyish or silver villous-tomentellous abaxially; sepals 6, indumentum as on bracteoles; outer sepals 0.6-1.3 × 0.4-0.7 mm, ovate or ovate-elliptic, base truncate, apex acute; inner sepals 1.2-2.2 × 1-1.5 mm, narrowly ovate, ovate, elliptic or weakly obovate, base obtuse or cuneate, apex acute to rounded, tip of inner sepals erect, sometimes reflexed past anthesis; petals 6, 0.6-1.2 × 0.3-0.8 mm, inner ones slightly smaller and narrower, obovate, obovate-trilobed or flabelliform, weakly to moderately concave, membranous, glabrous adaxially, sparsely silvery tomentellous abaxially, base cuneate or slightly clawed, lateral margins inflexed, partially clasping the filaments, apex acute, sometimes obtuse in the inner ones; stamens 6, filaments 0.4-0.8 mm long, inner ones slightly longer, clavate, free or connivent, less frequently connate ca. half their length, glabrous; anthers 0.2-0.3 mm long, erect, connective protruding adaxially and forming a hump or a horn apically or not, protrusion more conspicuous when older. Pistillate flowers (mostly old) 1.7-2.2 mm long, greenish; pedicels 1.3-5.1 mm long, terete, indumentum as on the axis; bracteoles 1-3(4), 0.2-0.6 × 0.3-0.6 mm, ovate or oblong, rather fleshy, glabrous adaxially, greyish or silvery villous tomentellous abaxially; sepals 6-9(12), weakly concave, moderately fleshy, in 2-3 whorls, glabrous adaxially, greyish or silvery villous tomentellous abaxially; outer sepals ca. 0.5-1.3 × 0.4-0.8 mm, ovate, base truncate, apex acute; middle sepals 0.6-2.2 × 0.6-1.4 mm, broadly ovate to obovate, base obtuse or cuneate, apex acute; inner sepals 1.6-2.2 × 1.3-1.7 mm, ovate, obovate or elliptic, base cuneate or clawed, apex obtuse or rounded, tips erect to weakly reflexed past anthesis; petals 3(4), 1.3-1.7 × 0.6-0.8 mm, spatulate or obovate-trilobed, weakly concave, membranous, glabrous adaxially, glabrous or sparsely silvery tomentellous abaxially, base clawed, apex obtuse; carpels 3, 0.6-0.9 × 0.4-0.6 mm, dark to light brown villose, trichomes appressed-ascending; style 0.6-1.1 mm long. Infructescences axes 1-6 × 0.3-0.9 cm long, at times moderately stout, brown to silvery-strigillose-tomentose or glabrous; fruiting pedicels 2.3-4.6 mm long, terete, sometimes rather thick; carpophores 4-8 mm long, clavate in mature fruits, truncate at apex, cream or brownish velutinous. Drupelets 1.8-2.8 × 1.2-1.6 cm, yellow when ripe, ellipsoid or weakly oblongoid, weakly eccentrically attached, base obtuse, stylar scar basal; exocarp 0.9-1.2 mm thick, surface rugulose, cream or silvery velutinous or glabrescent, granular when dried; mesocarp said to be "clear and slimy" (Berlin 542); endocarp 1.7-2.4 × 0.8-1.2 cm, chartaceous, surface reticulate by scarcely pronounced veins. Seeds with embryo 3.6-4.9 cm long, cotyledons unequal.

Distribution and ecology.

Known from the lowlands to mid elevations in eastern to central Peru (Fig. 21 ), including the departments of Amazonas, Loreto and Pasco, from elevations of 106 m in Loreto up to 1380 m in Pasco. Staminate plants were collected in January-February, July-August and November. Pistillate flowers were found in February, October and December, whereas fruiting specimens were found all year round.

Common names and uses.

Peru: “dabau” (Ancuash 660, ♂ fl, Kayap 749, imm fr, 1205, mat fr); “dúpam” (Berlin 542, mat fr); “tsegásnum” (Aguaruna) (Castro et al. 18929, imm fr; Lewis et al. 18475, imm fr); “namaú” (Kayap 156, mat fr); "tseas daek" (Kayap 1032, imm fr); “tsegas” (Kujikat 107, imm fr); “tseusnum” (Ancuash 1219, ♂ fl); "ampihuasca amarilla" (Schunke Vigo 2981, mat fr); "ampihuasca delgadito" (Schunke Vigo 6836, ♂ fl); "ampihuasca negra" (Schunke Vigo 7125, ♂ fl).

Note.

Krukoff and Moldenke (1938) cited Chondrodendron iquitanum ( Curarea iquitana in this study) as a "source of poison for darts of Indians" based on the label of the sterile Mexia 6321a. This specimen was later identified as Curarea toxicofera ( Barneby and Krukoff 1971). I have not examined the referred specimen and hence I have not been able to confirm its identity.

Etymology.

Presumably in reference to Iquitos, the largest city in Peruvian Amazonia and in which general area the type specimen was surely collected.

Conservation status.

The assessment was based on 37 collections corresponding to 18 localities that yielded an Extent of Occurrence (EOO) of 279,551 km2 and an Area of Occupancy (AOO) of 72 km2. The 18 localities represent 17 subpopulations of which four occur within protected areas (Allpahuayo-Mishana National Reserve in the Iquitos area) and three are found on private lands. Although Curarea iquitana is not abundant where it occurs, it is however broadly distributed and hence it is assigned a preliminary status of "Least Concern" (LC).

Discussion.

Curarea iquitana is here resurrected from synonymy under C. toxicofera . Curarea iquitana , as defined here, encompasses a broad range of morphological variation and includes, at least provisionally, what is labelled the allpahuayo group (al.) in the linear discriminant analysis. While the Curarea iquitana (iq) and allpahuayo (al.) groups may represent different entities, at present it is premature to recognise them as different species, given that the morphological quantitative characters evaluated in this study partially or completely overlap between the two groups (Fig. 10B ).

Additionally, features of pistillate flowers are still fragmentary or lacking, hence the extent of variation, if any, in these features, remains unknown. Collections from the foothills of central-eastern Peru in the Amazonas department from 200-800 m elevation closely resemble the type of Chondrodendron iquitanum Diels (Tessmann 4196), which was collected in the same general area - in the basin of the Marañon River, at 160 m in elevation - around which my concept of Curarea iquitana is centred. These collections tend to have conspicuously large, ovate or broadly ovate leaves with 5-7 main veins. The staminate inflorescences have a brownish to silvery strigillose indumentum and small flowers that range from 1.6 to 1.8 mm long, (mostly greyish villous and 1.3-1.8 mm long in the allpahuayo group). The adaxial horn-like protrusion of the connective at the apex of anthers, characteristic of Curarea iquitana , is variable amongst the studied collections, appearing as a horn (long and weakly incurved), as an apical-adaxial keel or as an adaxial hump, the latter more frequently being observed in the allpahuayo group; anthers are for the most part immersed in the connective. An old and fragmentary pistillate inflorescence of C. iquitana s.s. is a thyrse with brownish or silvery villous indumentum and the rugulose or muriculate drupelets have a golden-brownish velutinous-hispidulous indumentum. The only pistillate inflorescence known in the allpahuayo group has cymose primary branches proximally, distally these being reduced to single flowers giving the appearance of being racemose. The immature condition of the drupelets in most collections studied precludes their use in analyses of quantitative variation of the groups. Collections from non-flooded areas around Iquitos in eastern Peru, ca. 110-140 m in elevation and those from the Andean foothills in Pasco department, from 500-1380 m elevation, are here provisionally included in C. iquitana .

Selected specimens examined.

PERU. Amazonas: [Prov.] Condorcanqui, Río Cenepa, Camino Etseketal, norte de Huampami, monte, 600-800 ft, 31 Jul 1974, (♂ fl), Ancuash 660 (MO!, NY!); Prov. Bagua, Distrito Imaza, Región Nororiental del Marañon, Comunidad Aguaruna de Kusu-Listra , Cerro Apág, margen derecha Quebrada Kusú, 05°02'24"S; 078°19'12"W, 600-700 m, 17 Sep 1996, (imm fr), Díaz et al. 8239 (MO!); Rio Cenepa region , monte, orilla de Quebrada Huampami, 18 Jan 1973, (mat fr), Kayap 156 (MO!); Rio Cenepa , vicinity of Huampami, ca. 5 km east of Chavez Valdivia , Que Quebrada Najamtai entsa, en bosque primario, 04° 30'S; 78° 30'W, 200-250 m, 3 Aug 1978 (♀ fl & imm fr), Kujikat 107 (MO!); Comunidad de Yamayakat , Rio Maranon , bosque primario, 04°55'S; 078°19'W, 320 m, 15 Jul 1994, (♂ fl), Vásquez et al. 18715 (MO!) . Loreto: Prov. Maynas, Distrito de Indiana, campamento turístico de Explorama, bosque, 03°30'S; 073°14'W, 110 m, 10 Feb 1996, (♂ fl), Ortiz et al. 167 (MO!); ibid., 11 Feb 1996, (mat. fr.), Ortiz et al. 172 (MO!); Distrito de Iquitos, Estacion Experimental de Allpahuayo , IIAP, bosque, 04°10'S; 073°30'W, 120-140 m, 20 Feb 1996, (♂ fl), Ortiz 176 (MO!); ibid., 22 Feb 1996 (♂ fl), Ortiz 181 (MO!); ibid., 23 Feb 1996, (♀ fl), Ortiz 184 (MO!); ibid., 23 Feb 1986, (♀ fl, imm & mat fr), Ortiz 186 (MO!) . Pasco: Dist. Palcazu, Comunidad Nativa Alto Lagarto (Reserva Comunal Yanesha), remanente de bosque primario, 10°08'04"S; 075°22'06"W, 500 m, 9 Feb 2011, (mat fr), Rojas & Ortiz 7674 (HOXA n.v., MO!, USM!); Prov. Oxapampa, Parque Nacional Yanachaga-Chemillen, sector Alto Lagarto, remanente de bosque primario, 10°07'44"S; 075°26'41"W, 1380 m, 20 Aug 2011, (imm fr), Rojas et al. 7909 (HOXA n.v., MO!, USM!); Prov. Oxapampa, Gran Pajonal, trail between Chequitavo and Shumahuani, primary forest, 1200-1300 m, 10°45'S; 074°23'W, 30 Mar 1984, (mat fr), Smith 6584 (MO!) .

Figures

Figure 10. Linear discriminant analysis of characters from leaves, staminate inflorescences and staminate flowers of the five a priori groups of the Curarea toxicofera complex: A plot of scores of function 1 and function 2 B histograms of the first discriminant function values showing the positions of the five a priori defined groups, al. = allpahuayo, iq = Curarea iquitana, tm = Curarea tomentocarpa, to = Curarea toxicofera and uc = ucayali, respectively.

Figure 20. Curarea iquitana (photograph of the type of Chondrodendron iquitanum, Tessmann 4196, B).

Figure 21. Geographic distribution of Curarea iquitana and C. tecunarum, for the latter selected specimens only, because most of the specimens are sterile.