Kalanchoe [subg. Bryophyllum] sect. Streptanthae Gideon F.Sm.

Smith, Gideon F., 2023, Kalanchoe sect. Streptanthae (Crassulaceae subfam. Kalanchooideae), a new twospecies section in K. subg. Bryophyllum, Phytotaxa 609 (4), pp. 273-281 : 278-279

Kalanchoe [subg. Bryophyllum] sect. Streptanthae Gideon F.Sm. , sect. nov.

Type:— K. streptantha Baker (1887: 472) .

Designations not validly published:—“ Kalanchoe subsect. Streptanthae ” Boiteau (1947: 9), nom. inval. ( Turland et al. 2018: Art. 39.1). “ Kalanchoe [unranked, as “§ 8”] Streptanthae ” Boiteau & Mannoni (1949: 113), nom. inval. ( Turland et al. 2018: Art. 39.1).

Diagnosis:—Generally differs from other taxa included in K. subg. Bryophyllum by a combination of being non-bulbiliferous; by the presence of what appears to be sterile organogenic spots on the leaf margins; by having a cylindrical corolla tube that is distinctly constricted ± towards the middle; by the pedicels being cone-shaped, enlarging towards the calyx; by the segments of the apically early-wilting calyx being substantially fused; by the flowers, especially the calyx, often being pentamerous rather than tetramerous, or the calyx being pentamerous and the corolla tetramerous, with the tetramerous condition being by far most commonly found in Kalanchoe ; and by the anthers often protruding between the corolla lobes rather than at the mouth of the flower.

Included taxa:—As presently understood, only K. streptantha and K. bogneri . Infraspecific taxa are not recognised in K. streptantha at present, nor in K. bogneri , for that matter. However, material distributed through the International Succulent Introductions (ISI), ISI 2013-26 (see http://media.huntington.org/ISI/ISI2013/2013-26.html), reproductivemorphologically deviates from ‘typical’ K. streptantha , especially in terms of the “brick-red corolla tubes with flaring orange petals [corolla lobes]” ( Trager 2013: 58).

Description:—Perennial shrubs, robust, sparsely to densely branched, with haphazard canopies, succulent, to (0.4–)1.0– 1.2 m tall. Stem branched from base or higher up, robust, 10–30 mm in diam., ± erect to variously leaning, glabrous, light green when young, brownish to greyish when older. Leaves decussate, sparsely arranged, few to many especially towards terminal ½ to ⅔ of branches, slowly shed lower down, erect to gracefully curved upward and inward when young to variously horizontally spreading or spreading at 45° angle at maturity, glabrous, with very slight or dense, conspicuous bloom, sessile to ± very shortly petiolate, dull light green to glaucous-green to purplishinfused or with pronounced purplish spots, non-bulbiliferous; petiole ± absent; blade 40–140(–170) × 10–30(–55) mm, lanceolate-oblong to slightly obovate, ± flattened above, convex below, midrib prominent, succulent; base cuneate, somewhat amplexicaul; apex tapering to sharp but harmless tip; margins ± straight or slightly irregularly sinuate, edged with ± evenly spaced purplish or brownish spots especially abaxially or ± concolorous, transitional leaves on peduncle similar or lacking marginal spots. Inflorescence a terminal, few-branched, few- to many-flowered corymb, up to 30 cm long, rounded-head-shaped, erect throughout to gracefully leaning sideways; peduncle erect throughout, not nodding pre-anthesis; pedicels 6–20 mm long, stout to dainty, cone-shaped-enlarged towards calyx or the same width throughout. Flowers large, pendent, glabrous, often minutely brown-spotted, waxy bloom absent or present, elongated-globular in bud; calyx consisting of 4 or 5 sepals, persistent when dry, then papery, cream-coloured; sepals 18–22(–30) mm long, yellow or greenish, somewhat shiny, free lobes slightly red-infused, forming tube, fused for ± ¾ of their length, free portions clasping corolla tube or curved away from tube when drying, acute-tipped, free portions 5–9 × 4–7 mm, deltoid-ovate, glabrous, obscuring ± ⅓ to ½ of corolla tube; corolla tube 35–40(–49) mm long, yellow to yellowish green, more rarely pinkish yellow, or various shades of orangey red, ± cylindrical, distinctly constricted ± in middle, to ± straight, slightly tapering to mouth, scarcely to distinctly 4-angled; corolla lobes 4 or 5, 9–12 × 5–6 mm, ± ovate to ovate-oblong, erect to slightly to distinctly spreading at maturity, distinctly apiculate, same colour as tube, inside and to lesser extent outside of mouth red-veined. Stamens inserted in single series low down in corolla tube, at ± upper level of carpels, exserted ± 3–4 mm, often placed between corolla lobes; filaments ± 32–40 mm long, thin, light yellowish green, reddish-infused upwards; anthers ± 1.0– 1.5 mm long, greyish black, hastate, exserted, often protruding between corolla lobes rather than at flower mouth, often very obvious as black ‘spots’ when flower dries. Pistil consisting of 4 carpels; carpels 8–12 mm long, light yellowish green; styles 30–32 mm long; stigmas hardly capitate, light yellowish green; nectar scales ± vertically-rectangular, free, not connate, ± 2 × 1 mm, rounded above. Follicles 9–15 mm long, shiny light green to mid-green, remaining so for a long time, eventually turning dull greenish brown, then brittle, grass spikelet-like, splitting longitudinally, enveloped in dry, light yellowish to creamy white remains of calyx and corolla, wiry, dried styles persistent. Seeds 0.50–0.75 mm long, reddish dark brown to dark brown, ovate-cylindrical to banana-shaped-curved, slightly apiculate at one end, longitudinally striated. Chromosome number: 2 n = 34 ( Friedmann 1971: 104, Smith 2022b: 158, 168–169).