Kalanchoe peltigera Descoings (2005a: 6)

Shtein, Ronen & Smith, Gideon F., 2021, Taxonomy and nomenclature of the southern Malagasy Kalanchoe peltigera, with reference to K. rosei var. seyrigii (Crassulaceae subfam. Kalanchooideae), Phytotaxa 490 (1), pp. 47-59 : 52-54

Kalanchoe peltigera Descoings (2005a: 6)

Homotypic synonym:— Bryophyllum peltigerum (Desc.) Byalt (2008: 464) , syn. nov.

Type:—[ MADAGASCAR.] Ex hort. “ Origine: cette plante m’a été donnée par M. Philippe Richaud qui l’a récoltée aux environs de Tsivory au nord du bassin du fleuve Mandraré, dans le sud-est de Madagascar” [English: “ Origin: this plant was given to me by Mr. Philippe Richaud who collected it in the vicinity of Tsivory in the northern part of the Mandraré River basin, in southeastern Madagascar”], [ B.] Descoings 28316, (holotype P †). Neotype (designated here):—Clonally derived material from which Descoings 28316 was prepared, collected by Philippe Richaud, 1994, first cultivated in France, then cultivated and collected for preservation in Israel, R. Shtein 795, [ TELA927 ] (neotype TELA); R. Shtein 795 [ TELA928 ] (isoneotype TELA).

Notes on the type:—The holotype of the name K. peltigera is a specimen, B. M. Descoings 28316, undated but found during 1994 in Madagascar (Phillipe Richaud pers. comm.), which Descoings stated to have deposited at Herb. P ( Descoings 2005a: 6). However, this specimen is not extant at that repository (Florian Jabbour pers. comm.). Apart from the specimen B. M. Descoings 28316 no other material that would qualify as original in the sense of Turland et al. (2018: Art. 9.4) could be traced. We accordingly here neotypify (see above) the name K. peltigera on R. Shtein 795, a specimen held at Herb. TELA. This specimen was clonally derived from the original gathering from which the holotype was prepared.

Distribution:—the forests of northern Androy and Anosy, southern Madagascar ( Fig. 4 ).

Description:—see Descoings (2005a) for a description of K. peltigera . We here amplify the description with the following amendments and additions: Plant perennial to biennial, possibly up to 1.8 m tall. Leaves capable of producing bulbils on the entire dented part of the lamina margin (see ‘Taxonomic affinities’, below); lateral blade expansions / lobes as long as they are wide when measured from the curvature to the midline on the surface of the leaf.

Additional specimens examined:—[ MADAGASCAR.] Southeastern Madagascar. Belambo forest, between Bekily and Tsivory, 1944, André Seyrig 819; cited in Boiteau & Mannoni (1949: 71) under Kalanchoe rosei var. seyrigii , (P P-P00374207; https://science.mnhn.fr/institution/mnhn/collection/p/item/p00374207); P-P00444011, P- P00444012 (see “Discussion. 2. Aberrant herbarium material”, below).

Notes on the specimen Seyrig 819 cited under Kalanchoe rosei var. seyrigii :— Seyrig 819, i.e., P P00374207 ( Figs 1A and 5E ), a specimen here identified as belonging to K. peltigera , consists of two complete leaves with most of the petiole attached, as well as an inflorescence that lacks the base of the peduncle. Based on the preserved material and the notes of Seyrig attached to the specimen, the following description applies to Seyrig 819 (Seyrig’s notes have been translated from French and are given in italics; plant organs and/or structures are also given in italics):

Plants biennial, entirely glabrous, erect, at most 1.8 m tall. Stem at least 5 mm in diameter [5 mm towards inflorescence], cylindrical. Leaves opposite, decussate, petiolate; petiole [incomplete]> 3 cm long, 2–4 mm in diameter, cylindrical, slender, attached below lamina, 10–15 mm in from margin, slightly widening; blade 14–20 × 12–14 cm when pressed, 7–8 cm wide excluding basal lobes, peltate, at least somewhat guttered, widest basally, elliptic, ovate, uniformly green apart from darker margins, abaxially ornate with dark blotches, angled towards centre, originating between marginal serrations; base rounded to truncate, appearing hastate-trilobate with obtuse basal lateral expansions 6–7 cm long from petiole insertion, and 5–7 cm wide from lateral curve of blade to midrib; margin completely and regularly serrate, serrations 1–2 mm long, 3–4 mm wide, with some smaller secondary serrations towards middle of lamina; apex obtuse or rounded. Inflorescence corymbiform cyme,> 13 cm wide; bracts not seen, short-lived, drying and abscising when flowers reach anthesis; peduncle cylindrical, at least 15 cm long [full length uncertain], 3 mm in diameter, transitional leaves on peduncle not seen [drying and shed early]; pedicels 5–10 mm long, curved, cylindrical, attenuating towards flowers from>1.0–± 0.5 mm in diameter. Flowers 23–25 mm long, pendent. Calyx 16–17 mm long, ovoid, narrowest at flat base at 3–4 mm, up to 6–8 mm near sepals, widest in middle of free sepal segments, papery; calyx tube 11–12 mm long; free sepal segments 4–5 × 3–4 mm, ovate-deltoid, apiculate. Corolla ± 25 mm long, mostly uniformly pink, at least somewhat stipitate [stalk length cannot be observed]; corolla tube 17–18 mm long, cylindrical, somewhat widening towards base of petals to width of 4 mm, free corolla segments 7–8 mm × 4.0– 4.5 mm, ovate- or obovate-deltoid, barely spreading, hardly constricted at base, apically subacute, slightly apiculate. Styles and filaments reaching middle of petals [length cannot be observed]. Anthers dark-coloured.

Taxonomic identity of the specimen Seyrig 819 cited under Kalanchoe rosei var. seyrigii :—Like the species described as K. peltigera , material preserved under Seyrig 819 [P P00374207] represents a derived member of K. subg. Bryophyllum based on several floral characters. The flowers are pendent with a long and wide corolla tube as applies to K. subg. Bryophyllum , which was at the time treated as K. sect. Bryophyllum (Salisb.) Boiteau (1947: 8) . Within K. subg. Bryophyllum , the material differs from informal basal groups, for example the groups ‘Campanulatae’, ‘Centrales’, ‘Epidendreae’, and ‘Sylvaticae’ (see Boiteau & Allorge-Boiteau 1995: 16 [page unnumbered] and Allorge-Boiteau 1996: 141) included in the subgenus by a comparatively long and broad calyx tube. From K. [subg. Bryophyllum ] sect. Bryophyllum (i.e., the informal group ‘Proliferae’ of Allorge-Boiteau 1996: 141), Seyrig 819 differs in having smaller flowers, an inflorescence devoid of bracts at anthesis, shorter and less acute free corolla segments, as well as being entirely glabrous. Within K. [subg. Bryophyllum ] sect. Invasores, Seyrig 819 can be distinguished from all named infraspecific taxa in K. rosei by the relatively wide peltate, hastate-trilobate leaves with obtuse lateral expansions.

The leaves of K. rosei var. seyrigii and K. rosei var. variifolia are rarely lobed, and are usually articulate or truncate at most, or very slightly peltate, but then the petiole is attached to the blade at a distance of less than 5 mm from the basal margin of the leaf, as opposed to 10–15 mm in Seyrig 819. The leaves of the non-autonymic varieties of K. rosei are furthermore nearly flat and not highly incurved under high solar irradiation or recurved in shade. In addition, the leaves of the varieties (or as originally described, as subspecies) of K. rosei are much narrower than those preserved as Seyrig 819, with the latter having large, distinct, lateral expansions. The flowers of the material preserved as Seyrig 819 ( Fig. 5E ) differ from the flowers of K. rosei var. seyrigii and those of K. rosei var. variifolia by having a rounder calyx, by being broader (in terms of length:width ratio), by having a pink corolla (not orange to red), and by its different calyx proportions. The flowers of K. rosei var. rosei differ from those of Seyrig 819 in the proportions of the calyx—the calyx is much smaller in K. rosei var. rosei as compared to the whole flower (1:3 as opposed to 1: 2 in Seyrig 819); the free sepal segment:calyx tube ratio is approx. 1: 2 in K. rosei var. rosei as compared to 1: 3 in Seyrig 819, and the sepals are more acute in K. rosei var. rosei , and usually curve outward, a trait that was not observed in Seyrig 819.

Among all related species only K. rosei var. rosei and K. peltigera , as in Seyrig 819, possess hastate-trilobate leaves, typically 3- to occasionally 5(–7)-lobate, as well as guttered leaf blades that are highly incurved in sun or recurved in shade. However, in addition to the differences in flowers (see above), the leaves of K. rosei var. rosei are rarely more than slightly peltate (usually rather articulate) and much narrower, with the lobes and main leaf blade being triangular, rather than ovate to elliptic-oblong; lobes with width/length ratio of <1:2, compared to 1: 1 in Seyrig 819.

Among other representatives of K. sect. Invasores, Seyrig 819 differs from representatives of K. ser. Vilana Shtein & Smith (2021: 107), as well as from K. tubiflora ( Harvey 1862: 380) Hamet (1912: 44) [see Figueiredo & Smith 2017 on the nomenclature to be used for this species], K. × houghtonii Ward (2006: 94), K. × poincarei Raymond-Hamet & Perrier de la Bâthie (1913: 149) , pro sp., K. × rechingeri Raym.-Hamet ex Rauh & Hebding in Rauh (1995: 17), K. ×richaudii Descoings (2005b: 14), K. marnieriana H.Jacobsen ex L.Allorge in Boiteau & Allorge-Boiteau (1995: 102), K. laxiflora Baker (1887: 472) , K. fedtschenkoi Raymond-Hamet & Perrier de la Bâthie (1915: 75) , K. tenuiflora Descoings (2004:233) , K. waldheimii Raymond-Hamet & Perrier de la Bâthie (1915: 71) , K. serrata Mannoni & Boiteau (1947: 152) , and K. × lokarana Descoings (2005a: 16), by possessing wide peltate, hastate-trilobate leaves with obtuse lateral expansions, as well as pink corollas (compared to yellowish dull-coloured, or orange or red corollas). Seyrig 819 differs from K. daigremontiana Raymond-Hamet & Perrier de la Bâthie (1914: 128) , K. laetivirens Descoings (1997: 85) (treated as K. × laetivirens by Smith 2020: 105), and K. sanctula Descoings (1997: 87) , by having peltate leaves, as well as a far bigger calyx with different proportions (see above). It also differs from the latter three, as well as from K. tubiflora , K. × houghtonii, K. × rechingeri, K. × poincarei , and representatives of K. ser. Vilana, by not forming leaf bulbils constitutively.

Seyrig 819 coincides closely with K. peltigera and with three exceptions all the traits and measurement ranges observed in Seyrig 819 are present in the description of K. peltigera ( Descoings 2005a) . These are:

1. Descoings (2005a: 6) described K. peltigera as “annuele (?)” [English: “annual (?)”]. In the notes attached to Seyrig 819, Seyrig suggested that the material preserved is biennial;

2. Descoings (2005a: 6) gave the height of K. peltigera as “ 30–40 cm ”, while Seyrig gave an upper limit of 180 cm [or perhaps 1.0 m– 0.80 m; see below] for Seyrig 819. Where K. rosei var. seyrigii was first published and described, and reference was made to Seyrig 819 (i.e., not the type specimen), its height was given as 100 cm, including the inflorescence ( Boiteau & Mannoni 1949: 71).

3. The dimensions of the leaf material preserved as Seyrig 819 are 14–20 × 12–14 cm, as compared to 6–15 × 4–5 cm provided for the leaves of K. peltigera ( Descoings 2005a: 6) .

It is very likely that these three differences can be attributed to Descoings (2005a) only having had cultivated material at his disposal when describing K. peltigera . The type of the name K. peltigera , as noted by Descoings (2005a: 6), was prepared from a plant in cultivation that he received from Philippe Richaud who collected the material. The species was therefore obviously not studied in its natural habitat by Descoings. The assessment of the growth habit of K. peltigera was thus based solely on the growth of a potted plant in cultivation under greenhouse conditions in France. Seyrig, in contrast, collected and studied his specimen 819 in habitat. Material of a clone of the type of the name K. peltigera grown by one of us [RS] indicates that it is often perennial rather than biennial or even annual.

The second discrepancy between material preserved as Seyrig 819 and the description of K. peltigera can likely also be attributed to different growing conditions, as well as to intraspecific variability. While the cultivated material preserved as the type of the name K. peltigera reached only 40 cm, the height that the plants reach in habitat is unknown. The uncertainty of Descoings (2005a) regarding the duration of the life cycle of a plant suggests that he only grew it for one year before it was described. However, two year-old potted specimens of K. peltigera that reached a height of 0.8 m have been recorded by one of us [RS]. It is difficult to tell if Seyrig suggested a height range of 1.0– 0.8 m or an average height of 1 m and 80 cm for Seyrig 819 based on his notes alone, although according to the description included in the protologue ( Boiteau & Mannoni 1949: 71) of K. rosei var. seyrigii , the latter, “ 1.8 m ”, seems more likely. Even if the upper limit is interpreted as 180 cm, the described height range for the closely related K. rosei is also 30–180 cm sensu Descoings (2003).

Lastly, the type locality and thus far only known place of occurrence of K. peltigera is remarkably close to the place where Seyrig 819 was collected. Richaud collected material from which the type specimen of the name K. peltigera was prepared at Tsivory, in southern Madagascar, which is separated from where Seyrig 819 was collected by only about 50 km. This is a small enough range to suggest that Seyrig 819 belongs to the same entity that was eventually described as K. peltigera , and not to K. rosei var. seyrigii , and large enough to account for at least some infraspecific variation.

Apart from these three differences, all other measurement ranges and ratios are the same for Seyrig 819 and K. peltigera . Additionally, it seems that while lamina length is only marginally off from what is described for K. peltigera (1.5×), leaf blade width is off by a factor of 2–3. These differences can be at least partially explained by the material that was available for description; Descoings (2005a) described K. peltigera based on living material, while Seyrig 819 is a preserved herbarium specimen. Descoings (2005a: 6) notes that in K. peltigera “… les côtés du limbe fortement relevés en gouttière ...” [English: “… the sides of the leaf blade [are] strongly raised in a gutter …”]. Leaves so guttered would increase the width and length of the lamina when observed in a pressed, flattened specimen, so affecting the width more than the length, which would explain why the discrepancy in the width is on average 1.5× times greater than the discrepancy observed in the length. The pressed leaf blades of Seyrig 819 were at least somewhat guttered, based on the observed creasing. This is confirmed by the leaf blade measurements that Boiteau & Mannoni (1949) described for K. rosei var. seyrigii based on Seyrig 819, which are consistent with the description of K. peltigera ( Descoings 2005a) .

Figures

FIGURE 1. A. A specimen on which the original description of K. rosei var. seyrigii was based, but here is attributed to K. peltigera, Seyrig 819 (P P00374207). B–E. Living material of R. Shtein 795, a clone of the holotype of Kalanchoe peltigera in the collection of one of us (RS), cultivated in Israel: B. Inflorescence. C. Typical “shield”-like leaf shape. D, E. Lobed, more oblong leaves. Photograph credits: all Ronen Shtein, except A. Herb. P.

FIGURE 4. Occurrences of specimens historically associated with K. rosei. © OpenStreetMap contributors.

FIGURE 5. Comparison of leaves and flowers (inserts) of selected specimens of Kalanchoe rosei and K. peltigera, all elements to scale. A–B. Two specimens of K. rosei from the Onilahy region: A. P-P00444008 and B. P-P00444018. C–D. Two unusual specimens of K. peltigera from the Tsivory region: C. P-P00444011 and D. P-P00444012. E. Seyrig 819 (P-P00374207), a specimen of K. peltigera. F–G. Two specimens of K. rosei from between Tsivory and Behara: F. P-P00444006 and G. P-P00444003. H. Type of K. bouvieri, an abnormal form of K. rosei. I. Isotype of K. rosei (US00603536). Photographs of material held in the Vascular plants collection, Muséum National d’Histoire Naturelle, Paris (P) (A–H); and United States National Herbarium, Smithsonian Institution (US) (I).