Kalanchoe pumila Baker (1883: 139)

Smith, Gideon F., 2025, Taxonomy and nomenclature of Kalanchoe pumila (Crassulaceae subfam. Cotyledonoideae), a floury-leaved but otherwise glabrous species from Madagascar, and its synonyms, Phytotaxa 698 (4), pp. 257-268 : 259-264

Kalanchoe pumila Baker (1883: 139) ( Figs 1–2 and 4–5 ).

Also treated in:— Hamet (1907: 877 [9]); Hamet (1908: 25 [42]); Raymond-Hamet & Marnier-Lapostolle (1964: 21, Plate VI, Figures 11–12); Jacobsen (1977: 289); Jacobsen (1986: 626, Figure 882); Boiteau & Allorge-Boiteau (1995: 173–174); Rauh (1995: 92, Figure 222, 116, 157–158, Figures 413–416); Brickell (1998: 578); Brickell (2003: 594); Descoings (2003: 171); Bryant et al. (2005: 741); Brickell (2019: 617); Smith et al. (2019: 296); Smith & Figueiredo (2021: 100).

Type:— MADAGASCAR. Central Madagascar, without exact locality details, “Com. [Communicated]” in October 1882 by, [Reverend R.] Baron 2117, (lectotype, treated as “holo-K” [i.e., holotype, Herb. K] by Boiteau & Allorge-Boiteau (1995: 174), here corrected to lectotype, Herb. K barcode K 000232869 [image available online at https://plants.jstor.org/search?filter=free_text&so=ps_group_by_genus_species+asc&Query= K 000232869]), second-step lectotype here designated.

Isolectotype:— MADAGASCAR. Purchased June 1889, [Reverend R.] Baron 2117, (isolectotype, Herb. P barcode P 00431387 [specimen available for examination online at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00431387]).

Epitype:— MADAGASCAR. Antananarivo, “environs du petit Vontovorona à l’W de Tananarive”, altitude 1400 m, [ J. M.] Henri [ A.] Perrier de la Bâthie 18021, (epitype, Herb. P barcode P 00443582 [specimen available for examination online at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00443582]), epitype designated here ( Fig. 6 ).

Nomenclatural notes on the types of the name Kalanchoe pumila :—When publishing the name K. pumila , the only material that Baker (1883: 140) cited was “ Baron 2117!”, from “Central Madagascar ”. Until recently it was assumed that [Reverend R.] Baron 2117 refers to a single specimen and that this is the holotype of the name K. pumila (see for example Boiteau & Allorge-Boiteau 1995: 173–174, Descoings 2003: 171, and Smith et al. 2019: 296). However, as discussed in the next paragraphs, at least two specimens that were both collected by [Reverend R.] Baron under his collecting number “ Baron 2117!”, as cited by Baker (1883: 140) in the protologue of the name K. pumila , exist at Herb. K.

These two specimens, syntypes (see Turland et al. 2018: Art. 9.6 and Note 1 under Art. 40), were mounted on two different sheets. These specimens can be identified as follows:

1. A printed label stating: [Reverend R.] Baron 2117, Herb. K barcode K 000232869. “Com. [Communicated]” in October 1882. The specimen consists of a single, forked stem fragment, a single leaf, and a small piece of an inflorescence to which a few flowers are attached, as well as similar, unmounted fragments enclosed in a paper capsule. All of these are affixed to the detached upper right-hand corner of a standard herbarium mounting board.

2. A printed label stating: “ Madagascar. Rev . R. Baron, F.L.S. Purchased June, 1880”, with the number “2117” written by hand on the label, Herb. K barcode K 000232880. The specimen consists of a stem fragment with apically some leaves attached and a small inflorescence to which some flowers and a leaf-like bract are attached.

The type of the name K. brevicaulis Baker (1887: 470) —further discussed under ‘ Nomenclatural notes on the type of the name Kalanchoe brevicaulis :—’, below—was mounted on exactly the same mounting board used for no. 2, above, and has the Herb. K barcode K 000232881 affixed to it. These two, single sheet-mounted, specimens are separated by a near-vertical line drawn in pencil on the mounting board.

The two accessions identified as “1.” and “2.”, above, are not duplicates because they were evidently collected on two different dates. However, they were both clearly given the number [Reverend R.] Baron 2117 and both qualify as original material because they were obviously available to John Baker at Herb. K well before he published the name K. pumila in 1883.

Of these two specimens the [Reverend R.] Baron 2117 specimen that can be identified as Herb. K barcode K 000232869 is designated as the second-step lectotype of the name K. pumila , with the original typification of Boiteau & Allorge-boiteau (1995: 174) having been effective, but with “holo-K” here corrected to lectotype. Note that after the typification of Boiteau & Allorge-Boiteau (1995: 174) was published, Descoings (2003: 171) echoed their interpretation when he stated: “ T: Madagascar, Centre ( Baron 2117 [ K, P])”; he therefore also did not narrow down the effective lectotypification of Boiteau & Allorge-Boiteau (1995: 174). The abbreviation “ T: ” is simply defined as “(nomenclatural) type” in Eggli (2003: X).

Earlier, Hamet (1908: 25 [42]) treated “ R. Baron , no 2117” as the “Echantillon authentique!” of the name K. pumila . However, reference by Hamet (1908: 25 [42]) to “ R. Baron , no 2117” as the “Echantillon authentique!” of the name K. pumila has no nomenclatural standing as these two words are not equivalent to “ type ”; they only refer to a representative specimen. At any rate, more than one specimen is known to exist under [Reverend R.] Baron 2117.

An isolectotype, “ Rev . R. Baron No 2117 ”, exists at Herb. P barcode P 00431387[specimen available for examination online at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00431387]. It consists of only some leaf and flower fragments contained in a paper capsule affixed to a standard herbarium mounting board. The specimen was purchased, presumably from Herb. K, in June 1889.

The [ J. M.] Henri [ A.] Perrier de la Bâthie 18021 specimen of K. pumila with barcode P 00443582, held at Herb. P, is a considerably more complete specimen and, unlike the fragmentary original material, consists of three leafy terminal stem segments, each terminating in one or more inflorescences. This specimen is here designated as epitype ( Fig. 6 ).

Heterotypic synonyms:— Kalanchoe multiceps Baillon (1885: 469) .

Type:— MADAGASCAR. Région central. Fianarantsoa, Nord Betsiléo, Sirabé, “an sonnigen Bergafhängen” [sur les coteaux ensoleillés des montagnes / on the sunny mountain slopes], août [August] 1880, Comm. [communicated by] C. Rensch, received at Herb. P on 23 April 1883, J. M. Hildebrandt 3576 (lectotype, treated as “Holo-P” [i.e., holotype, Herb. P] by Boiteau &Allorge-Boiteau (1995: 174), here corrected to lectotype, Herb. P barcode P 00431388 [specimen available for examination online at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00431388]), second-step lectotype here designated.

Nomenclatural notes on the type of the name Kalanchoe multiceps :—The only material cited by Baillon (1885: 469) when he described K. multiceps was “ Hildebrandt, n. 3576, N.-Betsileo, Sirabé [ Madagascar]”. Herb. P holds two specimens of J. M. Hildebrandt 3576, and both have the same associated metadata. These two specimens have barcodes P 00431388 and P 00431389 and are syntypes under Turland et al. (2018: Art. 9.6 and Note 1 under Art. 40). In contrast to the statement of Boiteau & Allorge-Boiteau (1995: 174), the name K. multiceps therefore does not have a holotype. While their typification of the name K. multiceps was effective, in a second-step lectotypification the specimen with barcode P 00431388 is here designated as lectotype.

Despite including the name K. multiceps in the synonymy of K. pumila, Hamet (1908: 25 [41]), however, regarded “ J. M. Hildebrandt, no 3576”, likely in error, as the “Echantillon authentique!” of the name K. hildebrandtii Baillon (1885: 468) , a statement with no nomenclatural implications because these two French words at any rate do not equate to “ type ”. Note that Hamet attached a signed determinavit slip identifying the Herb. P barcode P 00431388 specimen, i.e., J. M. Hildebrandt 3576, as “ Kalanchoe pumila Baker ”, and not as K. hildebrandtii , as he stated in the text of his monograph ( Hamet 1908: 25 [41]).

Kalanchoe brevicaulis Baker : 470 (1887).

Type:— MADAGASCAR.Central Madagascar.Received [presumably at Herb. K]in November 1885. Rev . R. Baron 3542, (holotype Herb. K barcode K 000232881 [image available online at https://plants.jstor.org/search?filter=free_ text&so=ps_group_by_genus_species+asc&Query=k000232881]).

Nomenclatural notes on the type of the name Kalanchoe brevicaulis :—As far as could be determined, there is a single [Reverend R.] Baron 3542 specimen at Herb. K. Boiteau & Allorge-Boiteau (1995: 174) who regarded the [Reverend R.] Baron 3542 specimen, identifiable with barcode K 000232881 and held at Herb. K, as the holotype, are therefore followed here.

Hamet (1908: 25 [42]) treated “ R. Baron , no 3542” as the “Echantillon authentique!” of the name K. brevicaulis . Reference by Hamet (1908: 25 [42]) to “ R. Baron , no 3542” as the “Echantillon authentique!” of the name K. brevicaulis has no nomenclatural standing as these two words are not equivalent to “ type ”; they only refer to a representative specimen.

Descoings (2003: 171) did not provide the types of synonyms.

Kalanchoe pumila f. venustior Boiteau in Boiteau & Allorge-Boiteau (1995: 175).

Type:— MADAGASCAR. Antsirabe, Herb. Jard. Bot. 2058 (holotype, Herb. P).

Nomenclatural note on the type of the name Kalanchoe pumila f. venustior :—In Boiteau &Allorge-Boiteau (1995: 175) the holotype of the name K. pumila f. venustior was cited as “ Herb. Jard. Bot. 2058, Antsirabe, Holo- P ”. This specimen has not been seen during the present study.

Amplified description of Kalanchoe pumila —Perennial or short-lived multiannual, many-, later few-leaved, low-growing, branched, glabrous, epiphytic, lithophytic, or terrestrial succulent, to 300 mm tall. Stems rather brittle, branched or unbranched, erect to arched to leaning, ± round in cross-section, white-pruinose, later greyish, raised scars of abscised leaves conspicuous. Leaves opposite-decussate, sessile or very shortly petiolate, purplish pink, at first covered with a very fine, dusty, white-waxy-floury layer, wax later rubbing off older leaves exposing reddish blades, succulent, erect to erectly spreading; petiole absent or very short, 2–5 mm long if present, leaves not clasping the stem; blade 25–45 × 15–25 mm, obovate, ± flat to spoon-shaped turned up along margins, base distinctly cuneate, apex rounded-obtuse; margins from mid-leaf towards apex coarsely crenate or undulate-crenate into rounded, harmless teeth, white-waxy when young, purplish red when older. Inflorescence corymbose, short, erect, generally few-flowered, apically dense; peduncle greyish white-waxy; pedicels 6–12 mm long, slender. Flowers borne erectly to erectly spreading, distinctly twisted in bud; calyx consisting of 4 sepals; sepals 3–5(–7) × 1.0– 2.5 mm, green to strongly reddish purple-infused, densely white-waxy-covered, lanceolate to abruptly triangular, ± separate, basally fused for ± 0.5–1.0 mm, acute-tipped; corolla tube 5–10 mm long, light violet-pink to almost white, often well obscured by sepals, campanulate to suburceolate; corolla lobes 5–10 × 3–4 mm, light to dark violet-pink, longitudinally pinkishpurple-veined, ovate to oblong-ovate, prominent, spreading to strongly recurved, partly obscuring the corolla tube when recurved, mucronate. Stamens inserted well above the middle of the corolla tube, included to slightly exserted, prominently visible at the mouth; filaments 4–5 mm long, light greenish white, becoming thicker low down; anthers 0.40–0.75 mm long, reniform, conspicuously greyish to light to deep yellow. Pistil consisting of 4 carpels; carpels 8–11 mm long, bright light green, ± cylindrical; styles rather short, 1–2 mm long, light pinkish purple-infused; stigmas white, minute, distinctly capitate; scales 1.5–2.0 × 0.75 mm, shiny light green, erectly-oblong to columnar, round-tipped. Follicles (7–8) 9–12 mm long, light green to light greenish purple at first, drying greyish brown to black, becoming brittle, grass spikelet-like, enveloped in dry, purple to purplish to greyish brown remains of calyx and corolla, apically splitting star-shaped. Seeds (0.50–)0.75(–1.00) mm long, light reddish brown to dark brown to blackish brown, rather cylindrical. Chromosome number: x = 18, 2 n = 36 ( Friedmann 1971: 105); 2 n = 40 ( Van Voorst & Arends 1982: 577, 580), and see Smith (2022b: 174) for a discussion.

Figures

FIGURE 1. Kalanchoe pumila is an accepted species of low, shrubby growth habit. It characteristically has a dense, white-floury-waxy coating on its purplish pink leaves. Photograph: Gideon F. Smith.

FIGURE 2. The most commonly encountered variant of Kalanchoe pumila has flowers of which the adaxial corolla lobe surface is a bright pink colour. The corolla lobes are spreading or strongly recurved and conspicuously longitudinally purple-veined. Photograph: Gideon F. Smith.

FIGURE 4. The white-floury-waxy coating is prominent especially on the young, emerging leaves of Kalanchoe pumila, so affording them considerable protection against possible damage from high solar irradiation and heat loads. The waxy coating on the leaves eventually diminishes on older leaves through physical action, for example the impact of rain and wind, and because the leaf blades expand as they mature. Photograph: Gideon F. Smith.

FIGURE 5. Some variants of Kalanchoe pumila have flowers with the adaxial surface of the corolla lobes a muted pink to almost white colour. Photograph: Gideon F. Smith.

FIGURE 6. Epitype, [J.M.] Henri [A.] Perrier de la Bâthie 18021, Herb.P barcode P00443582 [specimen available for examination online at http://coldb.mnhn.fr/catalognumber/mnhn/p/p00443582]), designated in this paper, in support of the holotype of the name Kalanchoe pumila. Madagascar, “Antananarivo, environs du petit Vontovorona à l’W de Tananarive, altitude 1400 m.” Copyright of the Muséum national d’Histoire naturelle (MNHN—Paris, France), and reproduced with their permission, which is gratefully acknowledged.