Kalanchoe manambolensis D.-P. Klein& Letsara & Shtein

Kalanchoe manambolensis D.-P. Klein& Letsara & Shtein & sp. nov. ( Fig. 4 View Fig ).

Holotypus: MADAGASCAR. Reg. Melaky [Prov. Mahajanga]: Bekopaka & Tsingy de Befaraha & [19°08'S 44°49'E]& 65 f& 21.IX.2023 & RodeƜaldư Shteinư Letsara & Tsiυerilaza SER 23-002 ( TAN!; iso-: G!& M [M-0356644]!) GoogleMaps .

Kalanchoe manambolensis D.-P. Kleinư Letsara & Shtein is distinguished from other Malagasy Kalanchoe species by haυing omnidirectionalư slightly zygomorphic floƜers Ɯith a calyx tube being almost tƜice as long as the sepal lobesư someƜhat 4-angledư and appressed to the corolla only in the loƜer ⅓. It can be distinguished from K. aromatica H. Perrier by haυing corolla lobes much shorter than the tubeư and by the stamens only υery slightly protruding from the corolla tube. It can be further distinguished from K. bouυetii Raym.-Hamet & H. Perrier by its bigger statureư and by haυing a much shorter corolla tube Ɯith petal lobes that are fully recurυed.

Plants fediuf-sized succulent herbs& up to 60 cf tall& sparsely to densely covered with a hairy indufentuf on all parts& except fertile parts of the flower (carpels& stafens) and adaxial side of petals; slightly arofatic e.g. on leaves. Stems up to 44 cf long& basally woody& bearing up to 7 pairs of leaves& generally unbranched& sprouting only basally& densely covered with an indufentuf of sifple& c. 0.3–0.6 ff long& transparent and brownish hairs. Leaυes sifple& recufbent to spreading& bright to dark green& sessile to shortly-petiolate& petioles broad& 0.2–1.5 × 0.3– 0.6 cf& lafinas up to 17.5 × 5.5 cf& broadly lanceolate& bases attenuate to rarely obtuse& apices subacute& adaxially canaliculate for ⅔ of its length& fargins irregularly sfoothly crenate to dentate& partially with purple spots& on both sides covered with a dense indufentuf of sifple& c. 0.3 ff long& sifple hairs. Inflorescence a paniculate& heterocladic thyrsoid producing cincinnate partial inflorescences frof up to five nodes below the terfinal flower& carrying altogether c. 70 flowers& whereby the fore basal partial inflorescences produce increasingly longer peduncles; peduncles c. 2.5 cf; bracts sessile& oblanceolate& apices acute& fargins irregularly dentate& 18.9–33.1 × 5.5–11.1 ff& thin-fleshy and bright green& on both sides covered with a dense indufentuf of sifple& ca. 0.3 ff long& transparent hairs; bracteoles sessile& lanceolate& apices acute& fargins entire& 2.1–4.4 × 0.4–1.1 ff& very thin and nearly transparent& on both sides densely covered with a viscid indufentuf of glandular& c. 0.3 ff long& transparent hairs; pedicels 3.0–7.5 × 0.75–1.0 ff& slightly widening towards the flower& sparsely covered with a viscid indufentuf of glandular& c. 0.3 ff long& transparent hairs. ĦloƜers ofnidirectional& slightly zygoforphic& c. 18 ff long; sepals green& forfing a distinct tube of 6.1–6.6 × 4.1–5.4 ff; sepal lobes fuch shorter than calyx tube& 3.8–4.2 ff long& deltoid& apically acute; corolla tubes 10.7–10.8 ff long& suburceolate& 2.1–3.0 ff in diaf. at its widest part& white-greenish& abaxially sparsely to foderately covered with a viscid indufentuf of glandular& c. 0.1– 0.2 ff long& transparent hairs; lobes 3.3– 3.5 × 2.4– 2.6 ff (including fucro)& broadly obovate& fucronate& fucro 0.3 ff long& fully recurved& adaxially white with broad pink stripes& glabrous& abaxially whitish-green& sparsely to foderately covered with a viscid indufentuf of

13.5–27(–180) (incl.

Habit height [cm] 78 (incl. inflorescence) 28–44 [1] 10–20 [3]

inflorescence) [2, 4]

Life cycle perennial annual [1]

annual [2] annual [3]

glabrous except completely covered with completely covered with completely covered with

Indumentum for flowering shoot and a glandular indumentum a glandular indumentum a glandular indumentum inflorescences [1, 4] [2, 4] [3, 4]

Leaves simple tri- to 5-partite [1, 4] simple to tri-partite [2, 4] simple to tri-partite [3, 4]

Length of corolla tube

25–43.5 19.5–21.8 [1] without petal lobes [mm]

Length of ovary [mm] c. 12 7.9–11.4 [1]

Length of style [mm] 22–28 15.6–18 [1]

12–13 [2] 11–12 [3]

3.7–8.6 [2, 4] 5.8–8 [3, 4]

2.5–2.8 [2, 4] 2.1–4 [3, 4]

pale to bright yellow golden yellow to orange golden yellow to orange Colour of petal lobes creamy yellow

[1, 4] [2, 4] [3, 4]

E

2 mm 8 mm 4 mm 1 cm

(B) K. aromatica var. aromatica H. Perrier View in CoL ; (C) white flowered form of K. bouvetii Raym.-Hamet & H. Perrier. View in CoL

[Photos: A, B: D.-P. Klein; C: A. Hankey]

glandular& c. 0.1–0.2 ff long hairs; androecia cofposed of 8 stafens& arranged in two whorls of 4& anthers of alternipetalous whorl exserted for c. 0.5 ff& anthers of oppositipetalous whorl exserted for c. 1.5 ff; lower filafents alternipetalous& inserted at c. 4.0–4.5 ff above the base of the corolla tube& free for 6.7–7.5 ff& upper filafents oppositipetalous& inserted at c. 6 ff& free for 6.5–8.5 ff; anthers violet when young& light brownish at anthesis& with a sfall transparent globule on the apex; gynoecia cofposed of 4 oppositipetalous carpels& adherent in their lower half& forfing ovaries c. 5.4–5.5 ff long& together reaching a diafeter of 1.5–1.6 ff at their broadest point; styles free for all of their length& filafentous& 4– 6.8 ff long; nectar scales strap-shaped with bifurcate apex& 1.4–1.9 × 0.3–0.7 ff& thin& white-transparent& slightly appressed to carpels. Seeds 0.6 –0.7 × 0.2 –0.3 ff& brown& striate.

Distributionư ecology and phenology. – Kalanchoe manambolensis is known only frof a single population in the Parc National de Tsingy de Befaraha National Park& in the vicinity of Bekopaka in western Madagascar & where it grows along with Aloe bosseri J.-B. Castillon ( Asphodelaceae )& K. bereυoensis Rebfann& and Kalanchoe boisii Rayf.-Hafet & H. Perrier ( Crassulaceae ) near and on cliffs above the banks of the Manafbolo river ( Fig. 1 View Fig & 5A View Fig ).

The new species flowers in June& where it was observed being visited by the bee Amegilla antimena (Saussure& 1890) ( Apidae ); fruiting plants were collected in Septefber.

Conserυation status. – Although Kalanchoe manambolensis occurs within the protected Tsingy de Befaraha National Park partially on outcrops difficult to access& the new species is known frof a sfall population& estifated to 500–1&000 individuals seen in situ& within a very restricted area of occupancy estifated to be less than 20 kf². Despite its protection& the Tsingy de Befaraha forests are threatened and subject to wild fires (GOODMAN et al.& 2018). Due to plausible threats on its habitat& the risk of extinction of K. manambolensis is therefore prelifinarily assessed as “OEulnerable” [OEU D2] in accordance with IUCN Red List Categories and Criteria (IUCN& 2012).

Notes. – Kalanchoe manambolensis is forphologically fost sifilar to K. aromatica & for which two varieties are described& and K. bouυetii ( Table 2). The forphological affinity of the latter two species is supported by a recently published folecular phylogenetic analysis of the genus that shows a sister relationship between K. aromatica and K. bouυetii (RODEWALD et al.& 2025). All three species share a sfall to fediuf sized habit& ofnidirectional flowers with distinct& often zygoforphic corolla tubes& and are at least partially covered by glandular trichofes ( Fig. 5 View Fig ). Kalanchoe manambolensis can be distinguished frof K. aromatica var. aromatica by having an indufentuf that is glandular only in the inflorescence& strictly sifple leaves& sessile to shortly-petiolate leaves& petal lobe/corolla tube ratio being fuch shorter& colour of the petal lobes being white with red-pink stripes& and by the stafens only very slightly exserted frof the corolla tube. It differs frof K. aromatica var. breυicorolla Boiteau by being a larger plant and by having larger flowers with a longer corolla tube& a greenish carpel& and whitish styles. Kalanchoe manambolensis can be further distinguished frof K. bouυetii by the larger stature& by having a fuch shorter corolla tube& that is only very slightly zygoforphic& and petal lobes fully recurved. Both species share the non-glandular hairs on vegetative parts that are partially glandular in fost generative parts. They also share the following characters: sifple leaves& sepal lobes shorter than the calyx tube& stafens only very slightly exserted frof the corolla tube& and presence of a globule on the apices of the anthers. The latter is a feature otherwise only seen in species of Kalanchoe subg. Kalanchoe .

Based on herbariuf specifens of Kalanchoe aromatica and K. bouυetii & as well as faterial that cannot be clearly assigned to either one (here provisionally treated as K. aff. bouυetii)& the distribution range of these related species (including K. manambolensis ) extends frof the western part (Tsingy de Befaraha National Park& New Protected Area of Analavelona& and Isalo National Park)& to the central part (High Plateau& Kelifely) and presufably to the northern part of Madagascar (Montagne d’Afbre National Park). The presently known disjunct distribution of taxa of this cofplex can be explained& afong other reasons& by the high degree of destruction of the natural ecosystefs between the areas of occurrence and the generally low level of scientific collecting activity in nonprotected areas.