Notes: This species was originally described from a collection from Bolivia (Williams 2458). However, the whole range of geographic distribution and morphological variation in natural populations of this species was unknown at the time of its publication. For many years nobody was able to re-locate populations of R. cuneata growing next to the type locality in Bolivia, leading to taxonomic confusion. In particular, it was unclear whether specimens with more delicate and narrower stem segments with margins presenting narrower projections collected in Bolivia, Peru and Ecuador belonged to R. cuneata or not. Barthlott and Rauh (1987) preferred to recognize new collections from Peru and Ecuador of individuals that resembled R. cuneata as a new species (R. occidentalis), while Barthlott and Taylor (1995) named the thinner forms of R.cuneata from Bolivia as R. goebeliana. More recently, however, Bauer (2008) made new collections of specimens thought to represent R. cuneata, and R. occidentalis in Ecuador, Peru and Bolivia and cultivated those specimens under standardized conditions. Bauer (2008) observed that these specimens were very similar morphologically when cultivated under standardized conditions. Even the stem segments of R. cuneata from the type collection (larger and stouter, with margins with deeper projections) changed in cultivation demonstrating that the variation in stem morphology is likely phenotypic plasticity, resulting from varying environmental conditions and suggesting that all taxa listed above should actually be recognized as a single species. Only a narrow form of R. cuneata, from the Bolivian Chaparre seemed to maintain its morphological variation in cultivation, hence deserving to be treated as a subspecies (R. cuneata subsp. australis). Rhipsalis goebeliana was excluded from this context, as it was originally described from cultivated material with unknown provenance (see notes under this species).

4.1  RHIPSALIS CUNEATA subsp. CUNEATAEpiphyte in shaded habitat, 1 m long, branching apical or sub-apical. Stem segments flattened to triangular in longitudinal section, 0.5-1.5 mm diam, dark green, delicate, fragile, dimorphic, midrib 2-3 mm diam, cylindric; primary stem segments 13-14 cm long; wings 2-3, with cylindric base, 0.4-0.7 cm wide; secondary stem segments 5.5-17 cm long, base attenuate, apex truncate,wings 2(-3), 1.2-2.5 cm wide, margin serrate, plane, rare slightly undulate, with 2-5 mm projections. Areoles between margin projections, 1.7-3.8 cm apart, first of segment 4-8(-10) distant from segment base; when sterile 1 mm diam, with 2 acicular reddish scales; when fertile 1.5 mm diam, with 1-3 acicular scales, 1(-2) flowers/fruits. Flowers ca. 1 mm diam; pericarpel 2-4 X 2-3 mm, cylindric, greenish, glabrous or with sepaloid bract; with 1-3 sepaloid tepals, 0.3-1.5 mm long and 6 petaloid tepals, 3-4.2X2-2.3 mm, wide elliptic, patent to sub-erect, whitish, apex rounded, slightly cucullate, margin straight. Style 3-4 mm long; stigma with 3-5 lobes, ca. 1 mm long, ligulate, spreading. Ovules in 3 rows, funicle short (< 0.5 mm long). Stamens ca. 40, 1.5-2.5 mm long, internal shorter, internal erect and external facing inwards, white. Nectary ca. 0.4 mm long. Fruit 7-9 X 7-8 mm, globose, whitish, glabrous. Figure7: A, H.Notes; Rhipsalis cuneata subsp. cuneata can be distinguished from R. cuneata subsp. australis by the wider stem segments and deep projections in the margin.Habitat and distribution: Occurs in the eastern lower Andean slopes of Ecuador and Peru, reaching marginal Amazonian formations on lower elevations (200-1500 m). In Bolivia occurs in the "Yungas" of La Paz, Cochabamba and Santa Cruz. An old collection from Suriname was also analyzed. Although we did not examine specimens from other countries, it is possible that this species might also occur in Colombia and other countries of northern South America.Figure B.

Rhipsalis cuneata Britton and Rose   Cact 4: 246 (1923)

Desc from B&R 1923

• Plant - epiphytic on trees;
• Joints -  oblong to spatulate, 8 to 12 cm. long, thin, obtuse, cuneate at base, strongly crenate, naked at the areoles or with a bristle or two;
• Flowers  - so far as known solitary;
• Fruit -  globose, 4 mm. in diameter, naked.

Notes from Bradleya 13

DISTRIBUTION. Bolivia (La Paz): epiphyte in rain-forest, at 900-1700 m altitude.

A living collection was recently obtained by Pierre Ibisch, Univ. of Bonn, where it is now in cultivation. This species has thicker stems than its Andean allies R. goebeliana and R. occidentalis and in this respect closely resembles the Brazilian R. crispata.

Flower is potentially that of R. cuneata. (Photo copyright KAF 12-07)