Corresponding author: Miguel E. Leal (
Academic editor: Hugo De Boer
A new species of
Leal ME (2014)
In 2012, a specimen of
The specimens collected in the Luama Wildlife Reserve keyed out to the section of
Therefore in this study, I compared the specimens collected from the Luama Wildlife Reserve with
The collected specimens from the Luama Wildlife Reserve were compared to
Table
Comparison
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Plant | Succulent herb | Herbaceous Herb |
length | Up to 50(-60) cm | 10–17 cm |
Root system | Tuber | Tuber |
posture | Erect | Hanging |
Leaves arrangement | Spiral | horizontal |
lamina | Oblong, sub(ob)ovate, linear, elliptic, ovate | Subfalcate |
dimensions | 1–15×0.2–4.5 cm | 5–7×1.1.4 cm |
apex | acute to subacuminate or obtuse | Acute and micrunate |
base | cuneate, sometimes obtuse to rounded | asymetrical cunate and rounded |
margin | finely to rather coarsely dendate (to subcrenate) or sometimes serrulate | Entire to coarsely dendate |
surfaces | puberulous to hirstellous or to hispidulous | Glabrous, subspiculate, bicolorous |
lateral veins | 4–12, up to 25 pairs, often (fainly) loop connected, reticulum rather narrow | 5–7 |
petiole | (0-)0.1–0.2(-0.5) cm long | 1–2 mm long |
stipules | persistent, triangular to oblong, up to 5 mm long, sometimes foliaceous, puberulous | Not observed |
Inflorescences | solitary or sometimes in pairs | solitary |
Peduncle | (0.3-)0.5–2.5(-7) cm long, ca. 1–1.5 mm thick | 0.1 cm long |
minutely puberulous to hirstellous or to hispulous | glabrous | |
receptacle | discoid to broadly turbinate, sometimes, shallowly cup-shaped, suborbicular 0.5–2(2.5) cm in diameter | elliptic to round, 3–4 mm in diameter, patelliform |
outside sparsely, to densely minutely puberulous to hirtellous to hispidulous | glabrous | |
flowering face | (sub)orbicular, sometimes to subangular or almost elliptic, fringe up to 1 mm broad or absent | elliptic to round |
appendages | inner (=marginal) row numerous, triangular to subulate or filiform, up to 1–5(-7) mm long, forming a (sub)crenate rim, or indistinct and the rim entire to faintly repand, | triangular lobes, 1 mm |
outer (=submarginal) row, usually ca. 5–12 mm, less commonly more than 12, up to 23, or less than 5, down to 2, or even 0, (broadly) ligulate to filiform or sometimes subspatulate or oblong, (0.1)0.2–3.5(-8) cm long, up to 2.5 mm broad | subspathulate, 2–3 mm long, 0.5 mm broad | |
staminate flowers | ±crowed, tepals 2, puberulous with white, red-brown or almost black hairs, stamen 2, filaments ca. 0.3–0.5 mm long, slender | few, glabrous, stamen 2, filaments ca.0.1 mm |
pistillate flowers | several to many, free part of the perianth shortly tubular, puberulous with white, red-brown or almost black hairs, stigmas 2, filiform, ca. 0.2–0.3 mm long, equal or unequal in length, sometimes one of the stigmas strongly reduced or a single stigma | few, glabrous, stigmas 2, filiform, ca. 0.1 mm long, |
Endocarp | body tetrahedral to subglobose, ca. 2 mm long, tuberculate, pale brown | Not observed |
Based on the differences in vegetative morphology, the specimens from the Luama Wildlife Reserve can easily be keyed out from the sister species in the same section of
Haec species notabilis ab omnibus
The Democratic Republic of Congo, Katanga Province, Tumbwe Sector, Luama Wildlife Reserve, M.E. Leal 2551 (holo LWI, iso BR),
Lithophytes 10–17 cm long with a tuber 0.5 cm; stems aerial, hanging, glabrous; internodes 2.5–3 cm long; no white latex or translucent exudate. Stipules absent or deciduous without scars. Leaves distichous; blade narrowly subfalcate 5–7 × 1–1.4 cm, membranaceous, apex micrunate, base cunate, adaxial side glabrous and subspiculate, abaxial side white and glabrous; margins entire; petiole 1–2 mm long; venation brochidodromous; 5–7 pairs of secondary veins; tertiary veins scalariform. Receptacle elliptic to round, 3–4 mm in diameter, patelliform; margin greenish with triangular lobes (1 mm) and subspathulate appendages, 2–3 mm long; peduncle 1 mm long, glabrous. Staminate and pistilate flowers (7 to 8) tightly packed in receptacle: perianth short lobed, whit apex minutely 2–3 lobed, glabrous; stigma 0.1 mm long. Drupes and seeds are unknown.
A population of
This new species can be distinguished from any other
The new species is added to the existing key of
1 | Stems succulent and thick, internodes short; leaves subrosulate |
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1’ | Stems (semi-)succulent, or herbaceous, internodes long; leaves spaced, sometimes crowded at stem apices |
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2 | Plants stem hanging | |
3 | Plant lithophyte, multiple appendages |
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3’ | Plant epiphyte, one appendage |
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2’ | Plants stem erect to ascending | |
4 | Plants annual, without a rhizome or a tuber |
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4’ | Plants perennial, with rhizome or a tuber | |
5 | Petiole relatively short, (0-)0.1–0.2(-0.5) cm long |
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5’ | Petiole relatively long (0.2-)0.5–2.5(-3) cm long |
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The specimens were collected in late October.
The species is distributed in small populations within the type locality, and according to these demographic characteristics it merits the conservation status of endangered (EN).
The epithet
This study was financially supported by the Mac Arthur Foundation. The author is grateful to the Centre de Recherche en Sciences Naturelles (CRSN/Lwiro) for administrative support and to Phytokeys secretary for providing the essential references and the reviewers for their valuable comments.