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| Drosera xerophila A. Fleischm.
in Fleischmann, 2018.
DOI: 10.3372/wi.48.48106
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Abstract
Drosera xerophila A. Fleischm., a new species of sundew from Overberg District, Western Cape Province, South Africa, is described and illustrated together with details on its distribution, ecology, habitats and conservation status. The new species is morphologically compared with presumably closely related taxa. An identification key and synopsis are provided for all rosetted hemicryptophyte (”perennially growing”) Drosera species of the SW part of Western Cape Province, with synonymy, types, distribution (including maps) and citation of specimens and georeferenced photographs. The names D. aliciae Raym.-Hamet, D. curviscapa T. M. Salter and D. curviscapa var. esterhuyseniae T. M. Salter are lectotypified.
Key words: carnivorous plants, Drosera, Droseraceae, Fernkloof Nature Reserve, fynbos, new species, nomenclature, Overberg District, South Africa, sundew, taxonomy, typification, Western Cape Province
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| Fig. 2. Drosera xerophila – A: habitat in sandy fynbos vegetation in Fernkloof Nature Reserve; B: habit of plants in comparatively dry, quarzitic soil; C: leaf; note long marginal tentacles; D: rosette with developing scape; E: aged specimen with column of old leaf remnants; note burrow of a trapdoor spider in base of stem; F: inflorescence. – A–E: South Africa, Western Cape Province, Fernkloof Nature Reserve, 15 Sep 2006; F: in cultivation; all photographs by A. Fleischmann. |
Drosera xerophila A. Fleischm., sp. nov.
Diagnosis: — Related to Drosera esterhuyseniae (T. M. Salter) Debbert, but differs from that species in having broadly spatulate, decumbent, rosette leaves (leaves narrowly cuneate to rectangular, held upright at an angle of 70°–30°) and glabrous, emarginate to bifid stigmatic tips (stigmas entire, knob-shaped, papillate). Resembles D. aliciae Raym.-Hamet due to similar flat, rosetted habit and basally ascending inflorescence scape, but differs from that species in having well-pronounced, cuneate, eglandular petioles (3–)5–10 mm long (petiole 1–3(–5) mm long and hence leaves appearing almost sessile [“apetiolate”] in D. aliciae), in style arms entire or only shortly bifid in distal ⅓–¼ (style arms forking below middle, usually again bifid or tripartite in distal part) and fusiform seeds without terminal appendages (seeds narrowly fusiform with filiform appendage on micropylar and chalazal end).
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Ecology and habitats — Drosera xerophila grows in Sandstone Fynbos vegetation over Table Mountain Sandstone, on well-drained ground in sandstone gravel, in cracks of sandstone rock, or in sandy soils with little organic matter (Fig. 2A, B).
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Etymology — The specific epithet denotes the fact that this species prefers to grow on well-drained, drier, only slightly moist ground (xerophilus = dry loving). This is not unusual for several species of Drosera from Mediterranean areas in the S hemisphere, but contrasts with the “conventional”, largely N-hemisphere-based experience of sundews as typical bog plants.
Andreas Fleischmann. 2019. Drosera xerophila (Droseraceae), A New Species from Overberg District, South Africa, and An Overview of the Rosetted Hemicryptophyte Sundew Species from Western Cape Province. Willdenowia. 48(1); 93-107 (DOI: 10.3372/wi.48.48106
