Cissampelos arenicola M. Nee & R. Ortiz, 2014

Ortiz, Rosa del C. & Nee, Michael H., 2014, A new species of Cissampelos (Menispermaceae) from Bolivia and Paraguay, PhytoKeys 38, pp. 89-99 : 92-94

Cissampelos arenicola M. Nee & R. Ortiz sp. nov. Fig. 2

Diagnosis.

Cissampelos arenicola is distinguished from the remaining American species by its small, ovate- to subreniform-trilobed leaves and by its (6)8(10)-locular synandria. Its small leaves and viny habit superficially resemble the southern African Cissampelos capensis but differs by its (6)8(10)-locular synandria (vs. 4) and by sepals and petals located adaxial to the ventral slit of the carpel. The (6)8(10)-locular synandria of Cissampelos arenicola resembles that of African Cissampelos mucronata , from which it differs by its smaller (0.8-3 × 1.3-4 cm vs. 3.3-4.3 × 4.5-6.6 cm) leaves and its larger endocarp (6 × 7 mm vs. 4.3 × 4.7 mm).

Type.

BOLIVIA. Dpto. Santa Cruz. Prov. Andrés Ibáñez: along hwy from Santa Cruz to Abapó, 3 km S of crossing of railroad and 2 km S of bridge over Quebrada Peji, 17°58'00"S, 63°11'18"W, 450 m, 1 May 2001 (♂ fl), M. Nee, S. Knapp & J. M. Mendoza 51717 (holotype USZ; isotypes LPB, MO-6393940, NY, and to be distributed to K).

Description.

Twining, perennial; stems striate, the older ones woody and glabrous, the younger ones subherbaceous and sparsely silvery-pilose, unarmed, growing in tangled viny masses to at least 5 m high in shrubs and small trees, to 5 mm in diameter; plants dioecious or infrequently monoecious. Leaves spiral, ovate- to subreniform-trilobed, usually broader than long, 0.8-3 × 1.3-4 cm, leaves associated with the inflorescences usually much smaller, lateral lobes divergent, rounded at apex, terminal lobe rounded and apiculate to aristate at the apex, chartaceous to subcoriaceous, glaucous, sparsely silvery-sericeous on both surfaces to nearly glabrous, palmately 6-nerved, basifixed or subpeltate with petiole inserted to 0.1-0.4 mm from the margin; petiole 5-17 mm long, pulvinulate at both ends. Staminate inflorescences: dichasium or monochasium, 1-2 from axils on adult or young leaves along the main stem or on young leaves of secondary axillary branches, silvery-pilose, peduncle 1.3-4.9 mm long, main axis of monochasium 1.2-3.2 mm long, bracts linear, 0.4-1.5 mm long; staminate flowers 5-6(-17); pedicels 0.5-1.6 mm long; sepals 4-6, 1.0-1.5 × 0.7-1.2 mm, obovate, shortly connate at base, concave, slightly spreading at anthesis, light cream-colored throughout, silvery-pilose abaxially, glabrous adaxially; petals usually 1, patelliform to barely cupuliform, 0.9-1.1 mm in diameter, or less frequently 3-4 and obovate, 0.7 × 1.1 mm, free, light cream-colored throughout, sparsely silvery-pilose abaxially, glabrous adaxially; synandrium 0.1-0.2 mm high, (6-)8(-10)-locular, loculi connate, transversely dehiscent, and radiating from a peltiform connective; carpellode absent. Pistillate inflorescences: 3-5 flowers fasciculate in the axils of adult or young leaves, sparsely silvery-pilose; pistillate flowers with pedicels 1.3-1.8 mm long; sepals and petals adaxial to the carpel; sepal 1(2), 1.2-1.5 × 0.9-1.2 mm, obovate, light cream-colored throughout, moderate silvery-pilose abaxially, less densely so adaxially; petals 1 (-3), subreniform, when 2 or 3, the petals free or partly to fully connate, opposite to the sepal, 0.7-0.9 × 0.9-1.4 mm, light cream-colored throughout, silvery-pilose abaxially, glabrous adaxially; sepal and petal soon deciduous, staminodes absent; carpel 1, gibbous, obliquely borne on pedicel, silvery-pilose, style 0.2-0.3 mm long, stigma 3-5-lobed, erect to spreading. Drupe globose, ca. 8 mm in diameter, glabrous, turning orange then red at maturity; mesocarp juicy; endocarp 6 × 7 mm, suborbicular-bilaterally compressed, with one tiny circular perforation on the lateral faces, ornamentation obscure, consisting of a very low medial ridge and obscurely transverse ridges ( Fig. 3A ); condyle bilaterally compressed, septiform (sensu Ortiz 2012).

Distribution and ecology.

The species is at present known from southern Bolivia and northwestern Paraguay ( Fig. 4 ). All Bolivian collections are from similar habitats of the sandy dune systems southwest of the city of Santa Cruz on the main highway which runs south to Abapó and on to Camiri and to Yacuiba on the Argentinian border. In Paraguay the species was collected along ruta Transchaco and also near the border with Bolivia in the proposed National Park Médanos del Chaco, where it has been found in seasonal forests and in dunes. In Bolivia there are extensive sandy savannas and large active dunes, the most well-known being the "Lomas de Arena" recreation area 15-20 km SSE of the center of Santa Cruz de la Sierra. The area where the species has been collected is on the western edge of this dune field. Plants were collected from 300-470 m elevation.

Pollination.

No observations of pollinators are available, nor notes on any possible odor. The extremely small size of the flowers suggests that a very small insect must be involved in pollination. Label note of Nee 51401: "It is difficult to separate the sparse and inconspicuous flowering and immature fruiting material from the vegetative mass".

Phenology.

Male flowers were collected in February, May, November, and in December, pistillate flowers and mature fruits in February, April, June, and in December.

Etymology.

From the Latin, arenicola, dweller in sand, as the species seems to be restricted to sandy savanna soils and edges of dunes.

Preliminary conservation status.

Cissampelos arenicola is at present known from 13 collections at nine localities from southern Bolivia and northwestern Paraguay. The sandy savannas in the area surrounding Santa Cruz de la Sierra are frequently burnt and heavily grazed by cattle. This appears to have little effect on the native vegetation, but development of the land for subdivisions and chicken ranches is a greater threat and is destroying much of the original vegetation. Although the Viru-Viru pampa surrounding the international airport north of the city of Santa Cruz is maintained as a natural savanna, Cissampelos arenicola has never been collected there. In Paraguay, Cissampelos arenicola has been collected in habitats described as seasonal forest, but also in areas with nomadic sand dunes. Thus, the “ephemeral” condition described on the labels may refer to its dynamic and transient habitat and not to the plant per se. Because of the fragmented and threatened habitat in Bolivia, its reported ephemeral condition of its habitat in Paraguay, and its usually small population sizes, Cissampelos arenicola may be considered as vulnerable.

On the other hand, by applying the IUCN Red List Criteria ( IUCN 2012), Cissampelos arenicola falls in the category of Endangered (EN) and meets the following criteria: A2c, as much as 50% decline of the population during the next 50 years inferred by the decline in habitat quality in the area of occupancy; B2c(ii,iii,iv), at present the area of occupancy is estimated as less than 500 km2, moreover, there are likely to be extreme fluctuations in the area of occupancy because of its unstable habitat.

Paratypes.

Bolivia. Santa Cruz: Prov. Andrés Ibáñez, along Quebrada Peji, vic. bridge of new hwy from Santa Cruz to Camiri and railroad bridge, 17°57'30"S, 63°11'00"W, 440 m, 11 Dec 1994 (imm & mat fr), Nee 45861 (LPB, NY!, USZ); along hwy from Santa Cruz to Abapó, 3 km S of crossing of railroad and 2 km S of bridge over Quebrada Peji, 17°58'S, 63°11.3'W, 450 m, 27 Feb 1998 (♂ fl, imm fr), Nee et al. 48487 (LPB, NY!, USZ); 15 Nov 2000 (♂ fl, imm fr), Nee 51401 (NY); along hwy from Santa Cruz to Abapó, 5.4 km S of turnoff at "km 13", 17°55'S, 63°15'W, 470 m, 18 Apr 1998 (imm fr), Nee 49044 (LPB, NY!, USZ); Prov. Cordillera, a 3-4 km al S de Puerto Guaraní, al norte de la frontera Paraguaya, sabanas planas, partes húmedas, 20°30'S, 62°15'W, 400 m, 19 Jun 1992 (♀ fl & mat fr), Mostacedo et al. 385 (MO!, USZ). Paraguay. Alto Paraguay: Fortín Teniente Montania, seasonal forests and swamps on clay soils, 22°03'15"S, 59°57'14"W, 5 Feb 2002 (♂ fl), Zardini & Guerrero 57845 (MO!). Boquerón: Ruta Transchaco, a partir del km 702, entre PN Tte. Enciso y PN Médanos del Chaco, ambiente ruderal, 20°36'19"S, 62°02'54"W, 22 Feb 2006 (♂ fl), De Egea et al. 923 (FCQ, BM, CTES, G, MO!, PY, SI, UNR); proposed National Park Médanos del Chaco, ephemerals on dunes, 20°41'03"S, 61°57'37"W, 300 m, 12 Dec 1998 (♂ fl), Zardini & Duarte 49600 (AS, MO!); (mat fr), Zardini & Duarte 49630 (AS, MO!); 13 Dec 1998 (♀ fl & imm fr), Zardini & Duarte 49829 (AS, MO!). Nueva Asunción: 5 km después del Destacamento, sobre vegetación, 19 Mayo 1993 (♂fl), Degen & Mereles 2969 (MO!). Presidente Hayes: Tyto Villazón, Fortín Guaraní, en espatillar arenoso, [22°44'S, 59°30'W], 2 Feb 1993 (♀ fl & mat fr), Mereles & Degen 5075 (FCQ, MO!).

Figures

Figure 2. Isotype of Cissampelos arenicola M. Nee & R. Ortiz (Nee et al. 51717, MO).

Figure 3. Endocarp ornamentation of A Cissampelos arenicola M. Nee & R. Ortiz (F. Mereles & R. Degen 5075, MO) B Cissampelos capensis L. f., (W. Giess et al. 5247, MO) C Cissampelos mucronata A. Rich., (Muller & Biegel 2281 MO). Scale bars = 3 mm.

Figure 4. Distribution of Cissampelos arenicola M. Nee & R. Ortiz, based on examined collections with coordinates.