Kalanchoe deliae Gideon F.Sm., 2023

Smith, Gideon F., 2023, Kalanchoe deliae (K. [subg. Kalanchoe] sect. Raveta; Crassulaceae subfam. Kalanchooideae), a new species from the Barberton Centre of Endemism in northeastern southern Africa, Phytotaxa 632 (2), pp. 131-142 : 133-137

Kalanchoe deliae Gideon F.Sm. , sp. nov. ( Fig. 1 )

Type:— SOUTH AFRICA. Mpumalanga province. Central-east region of the province . On a moderately sloped , north-facing , rocky ridge , in well-drained shallow soil among chert rocks in grassy vegetation, collected by Mrs Delia Oosthuizen on 06 May 2018, specimen prepared from cultivated material on 07 July 2023, G.F. Smith 1215 (holotype, Herb. PRU).

Diagnosis:—Plants of Kalanchoe deliae ( Fig. 1 ) are bi- to triennial to perennial through basal suckers and can be separated from K. luciae ( Fig. 2 ) as follows: K. deliae is less robust than K. luciae in all vegetative respects, with especially the leaves of the former [80– 140 × 55–60(–70) mm] not attaining the dimensions of the latter [60–160 × 30–190 mm]. The sepals of K. deliae can be up to 11 mm long, i.e., as long as the corolla tube, while those of K. luciae are only about 5 mm long. The adaxial surfaces of the rarely recurved, erecto-patent corolla lobes of K. deliae are light green and light rusty brownish-infused towards the tips, whereas those of K. luciae are white to pale yellowish and reflexed to completely flattened against the corolla tube, only sometimes suberect. The anthers of K. deliae are brown in bud, while those of K. luciae are yellow, and the pistil of the former is elliptic and bulged in the centre, whereas that of the latter species is prolate. Kalanchoe deliae has transversely oblong nectar scales, while those of K. luciae are ± square.

Description:—Bi- to triennial to perennial, few- to many-leaved, unbranched at first, sometimes pre- and / or postflowering slowly sprouting from near hard-herbaceous base, glabrous, distinctly waxy, medium-sized, 0.75–1.00(– 1.25) m tall when in flower, succulent. Roots fibrous to slightly thickened. Stems uniformly light green, not reddishinfused, unbranched higher up, erect to leaning, round in cross-section. Leaves opposite-decussate, light green, infused with rusty brown towards and along leaf margins only, succulent, erect to slightly erectly spreading, coriaceous and papery-flimsy on drying; petiole absent; blade 80–140 × 55–60(–70) mm, obovate to broadly elliptic, ± flat, sometimes floppily wavy, sometimes very slightly curved up along margins; base ± cuneate, sometimes very slightly auriculate, amplexicaul, leaves in a pair not connate basally; apex rounded-obtuse; margins smooth, sometimes very slightly saucer-like curved upwards. Inflorescence erect to leaning, club-shaped, apically very dense, many-flowered, short-branched thyrse consisting of several dichasia terminating in monochasia, flowering portion 110–130(–150) mm long, branches opposite, rarely only one at node, erect to slanted away from main flowering stem at angle of 10–15°, subtended by leaf-like bracts, sometimes with leafy branchlets in axils, axis light yellowish green to greyish green, very densely white-wax-covered; pedicels (2–)3–7(–10) mm long, slender. Flowers erectly spreading to slanted horizontally at anthesis, not or very rarely pendulous, not diurnal; calyx uniformly light green, very densely white-wax-covered; sepals 4, 7–9(–11) × (1.5–)2.0–2.5(–3.0) mm, light yellowish green to greyish green, rusty brown-infused towards apex, hardly contrasting against corolla tube, narrowly triangular-lanceolate, succulent, distinctly free above, diverging from corolla tube above, basally fused for <1.0 mm, acute-tipped; corolla 9–11 mm long, slightly enlarged lower down, gradually tapering to mouth, not twisted apically after anthesis; tube 8–10 mm long, light yellowish green to greyish green, fading rusty brown when spent, narrowly elongated-urceolate, rather distinctly 4-angled, round when viewed from below, longitudinally indistinctly fluted above; lobes (2.0–)2.5 × 3.0 mm, light green, light rusty brownish-infused towards tips, with margins usually paler, concolorous in bud, triangular, tapering towards acute apex, margins slightly to distinctly in-folded, erecto-patent, rarely recurved. Stamens 8, inserted in two ranks, one rank just above middle of corolla tube, other well above middle of corolla tube towards mouth, all 8 slightly exserted for 0.5–1.0 mm, visible at mouth; filaments 3–5 mm long, light green, thin, tapering upwards; anthers 0.5–0.6 mm long, browncoloured in bud pre-anthesis. Pistil consisting of 4 carpels, elliptic, bulged in centre; carpels 5–6 mm long, dull midgreen, strongly brown-infused; styles 1–2 mm long, brown-infused; stigmas very slightly capitate, brown, positioned at mouth; scales 1.0– 1.5 mm high, 1.75–2.00 mm broad, uniformly light greenish yellow, transversely oblong, narrowing towards base, flat and minutely repand above, slightly contiguous, arranged in virtually continuous ring. Follicles 7–8 mm long, light green at first, enveloped in dry, light yellowish green to greyish green remains of corolla, eventually brittle, grass spikelet-like with remains of corolla then rusty brown, splitting star-shaped. Seed 0.75–(1.00)–(1.25) mm long, reddish brown to dark reddish brown, very faintly striated, ellipsoid to more rarely somewhat banana-shaped. Chromosome number: unknown.

Distribution and habitat:—Except for the most general, no locality data from specimens or field observations are given. This deviation from widely followed taxonomic practice is justified by the fact that poaching of succulent plants from the wild in South Africa is a severe and escalating problem, and it was decided not to provide any information regarding the exact whereabouts of this new species that could cause known populations to be targeted for destructive collecting ( Smith et al. 2023b).

As far as presently known, K. deliae is restricted to the central-east Mpumalanga province of South Africa, which falls in the Grassland Biome ( Mucina et al. 2006: 349–436). The specific vegetation type is Barberton Montane Grassland (Gm 17) ( Mucina et al. 2006: 404–405), which is a mosaic of short grassland and rocky shrubland set in typically rugged, mountainous terrain ( Fig. 6 ).

As far as is presently known, the entire known natural geographical distribution range of K. deliae falls within the Barberton Centre of Endemism (BCE) ( Van Wyk & Smith 2001: 116–119), where it co-occurs with K. luciae , albeit with the latter preferring lower elevations. However, K. luciae has a much wider natural geographical distribution range in southern and south-tropical Africa (see Smith et al. 2019a: 188–194, Smith & Figueiredo 2021b: 208, 213, and Smith & Figueiredo 2023: 76, 78).

Flowering time:— Kalanchoe deliae flowers mainly in the late-autumn and winter months, from April to August, with a peak from May to June, in the southern hemisphere.

Eponymy:— Kalanchoe deliae is named for Delia Oosthuizen née Beukes (20 July 1969 –) ( Fig. 7 ). With a keen interest in botany and while based in the BCE ( Van Wyk & Smith 2001: 116–119), Delia started collecting plant specimens in 2013 and soon thereafter established the Barberton Mountainlands Nature Reserve Herbarium, where she is involved in the expansion, and physical and scientific curation of the collection. The focus of the Herbarium is the plants of the BCE and the Mountainlands Nature Reserve. From 2017 to 2021 Mrs Oosthuizen was an honorary research associate at the School of Animal, Plant and Environmental Sciences at the University of the Witwatersrand, and collaborated in several projects that included the description of novelties she collected. She was also the chairperson of the Mpumalanga Plant Specialist Group in 2018 and still serves on its committee. Having become known for her regional botanical knowledge she serves as a contact point for botanists working on specific taxa, as well as for researchers in other fields, including ecology, general biodiversity studies, geology, and vertebrate and invertebrate zoology. She also contributes to the management, communication and marketing activities of Mountainlands Nature Reserve, Barberton Makhonjwa World Heritage Site, and the region in general with an emphasis on plant diversity.

Figures

FIGURE 1. Kalanchoe deliae from central-east Mpumalanga, South Africa. A. Lower, leafy section of a stem. The opposite-decussate, amplexicaul, erect to slightly erectly spreading leaves are infused with rusty brown along the leaf margins only. B. Leaves are light green, obovate to broadly elliptic, sometimes very slightly curved up along margins and have a ± cuneate base that is sometimes very slightly auriculate. C. Roots are fibrous to slightly thickened and the stems are a uniform light green colour. D. The erect to leaning, club-shaped inflorescences are apically dense- and many-flowered. E. The flowering portion of the inflorescences is 110–130(–150) mm long and the branches are borne oppositely, with the branches slanted away from the main flowering stem at an angle of 10–15°. The internodes are very short, so yielding dense-clustered inflorescences. F. All plant parts are densely white-wax-covered. The adaxial surface of the corolla lobes are light green and light rusty brownish-infused towards the tips, with the margins usually paler. All photographs: Gideon F. Smith.

FIGURE 2. Kalanchoe luciae. A. Plant in flower.The inflorescence has a dense white-wax covering. B. Pseudo-rosette showing intensely red-infused leaves. C. Terminal portion of an inflorescence. The internodes are long, so yielding inflorescences with ± regularly spaced flower clusters. D. The adaxial corolla lobe surface varies from white, as here, to pale yellowish. In orientation the corolla lobes generally vary from strongly reflexed to completely flattened against the corolla tube, as here. Note how the corolla tubes bulge in the centre. All photographs: Gideon F. Smith.

FIGURE 6. A scorched specimen of Kalanchoe deliae at its type locality after a veld fire moved through its natural grassland habitat. Photograph: Gideon F. Smith.

FIGURE 7. Delia Oosthuizen (1969–) for whom K. deliae is named. Photograph: Gideon F. Smith.