See Calvente thesis 2010
7. RHIPSALIS MICRANTHA (Kunth) DC., Prodr. 3:476. 1828.
Cactus micranthus Kunth in Humb., Bonpl. & Kunth, Nov. Gen. Sp.
4: 65. 1823. -TYPE:
PERU. Olleros: "Crescit in arboribus", 1330m, Humboldt &
Bonpland s.n. (holotype: P!; isotype: P!).
Rhipsalis werkleii Berger, Monatsschr. Kakteenk 16: 64. 1906.- TYPE:
The Alwin Berger Succulent Herbarium, Alwin Berger s.n. (lectotype,
here designated : NY386146!)
Rhipsalis roseana Berger, Z. Sukkulentenk. 2: 22. 1923.-TYPE: The Alwin
Berger Succulent Herbarium, Alwin Berger s.n. (lectotype, here designated:
Notes. Rhipsalis micrantha is very diverse morphologically. Its morphological
diversity is linked with geography, altitude ranges and with the spatial
distribution of its populations, perhaps as a result from the Andean
discontinuous mosaic of environmental conditions and isolated microhabitats.
The four geographically isolated and morphological distinct populations
micrantha are here recognized as four subspecies: R. micrantha subsp.
micrantha, R. micrantha subsp. rauhiorum, R. micrantha subsp. tonduzii,
and R. micrantha subsp. monticola. The fact that no molecular variation
was found among subspecies (Calvente et al. in prep.), suggests a rapid
diversification. Apart from differences in geographical distribution,
variation in stem morphology is also important to diagnose subspecies.
Despite that, all subspecies of R. micrantha are difficult to be separated
in the herbarium because the diagnostic features are often lost during
the herborization process.
7.1. RHIPSALIS MICRANTHA subsp. MICRANTHA
Lithophyte or epiphyte in open habitat, 0.6 m long, branching apical
or rare sub-apical. Stem segments flattened to triangular in longitudinal
section, 2-3 mm diam, olive green, sometimes with reddish margin, succulent,
dimorphic, midrib 3-4 mm diam, cylindric; primary stem segments 20-25
cm long; wings 3-4, 0.4-0.5 cm wide; secondary stem segments (6.5-)-8-12(-15)
cm long, base attenuate, apex truncate; wings 2-3, 0.4-0.5(-0.7) cm
wide, margin slightly
serrate, plane, with 1-2 mm projections. Areoles between margin projections,
0.9-4.5 cm apart, first of segment 1(-2) cm distant from segment base;
when sterile 1.5-2 mm diam, with vestigial hairs; when fertile 2 mm
diam, with 1-2 acicular scales and scarce hairs at margin, 1 (-3) flowers/fruits.
Flowers ca. 10.5 mm diam; pericarpel ca. 4 X 3 mm, cylindric, greenish,
glabrous; with 1-2 sepaloid tepals, 0.5-1 mm long and 7 petaloid tepals,
(2-)5-6 X 2-3 mm, oblong to elliptic, patent or sub-erect, whitish,
apex rounded, slightly cucullate, margin straight. Style 4.5 mm long;
stigma with 5 lobes, 1.5 mm long, ligulate, curved, sub-reflexed. Ovules
in 5 rows, funicle short (< 0.5 mm long). Stamens ca. 35, 2-4.5 mm
long, internal shorter, spreading, whitish. Nectary ca. 0.5 mm long.
Fruit 5.5-6.5 X 5-5.5 mm, obovate, elongate, white, glabrous. Figure
Notes; R. micrantha subsp. micrantha is characterised by the succulent,
mostly 2-winged stem segments, as well as narrow wings and margins with
narrower projections than R. micrantha subsp. rauhiorum.
Habitat and distribution: Occurs in the highland Andean forests of
Ecuador and Peru, from 1000-1800 m. Figures 8, 9.
Rhipsalis micrantha (HBK) DC. Emend Barthlott in Trop. Subtrop. Pflanzenw.
10:7 (1974) forma micrantha Barthlott and Taylor in Bradleya 13 (1995)
Desc from Trop. Subtrop. Pflanzenw. 10:7 (1974)
Plant - epiphytic, rarely half-erector mostly pendent 1.5 m long, succulent
linear branches growing from the tips, 2 - 3 angled, 7 - 18 cm long
and 0.7 - 1.3 cm wide.
Areoles - very small without bristles, with barely visible tomentum.
New shoots with very small deciduous leaf and often with 1 mm long extranuptial
Branch covering - dirty green with long areas of 70? wide and 100? -
500? vesicles with polished surface area, stomata not sunken..
Flowers - simple, lateral, on the edges of the branches, whitish hence
shiny, radial, 6 -10 mm ?, more than half opening.
Perianth-segments - 5 - 7, the inside ones to 4.8 mm long and 4 mm wide,
egg-shaped or long-egg-shaped
Style - erect, 4 - 5 mm long with 3 - 4 spreading papillose lobes, a
white disk at the base of the style.
Stamens - 25 - 35 , 2 - 3 mm long, anthers white, small.
Pericarp - light-green, not sunken in the stem, bare, exceptfor a single
Fruit - a globose naked berry, 8 mm long, 6 mm wide white, most times
reddish towards the top.
DISTRIBUTION - Costa Rica, Colombia, western Venezuela, Ecuador, northern
Peru; near sea level to 2000m altitude De Candolle in Prodromus Systematis
Naturalis Regni Vegetabilis 3 : 475-476. 1828
7. R? MICRANTHA (H.B. et Kunth nov. gen. am. 6. p. 65. sub Cacto.)
ramosa, ramis 3-4-angularibus vel compresso-anticipitibus, floribus
ex angulis ortis. ? in
arboribus propè Olleros Quitensium. Flores albi minuti. †.
Translation into English
Plant pendulous, glabrous branches, branches 3 – 4 angled or flattened
in the front, flowering from the angles. growing on trees near olleros,
Quito, Peru. flowers small white. Specimen deceased
Treated as R. micrantha fa. micrantha by B&T in Bradleya 13