Aloe perfoliata Linnaeus (1753: 319)

Smith, Gideon F., Klopper, Ronell R., Woudstra, Yannick & Grace, Olwen M., 2025, A further step towards stabilising the nomenclature associated with the genus name Aloe (Asphodelaceae subfam. Alooideae): the legitimate name A. perfoliata and the illegitimate name A. mitriformis are based on the same type, with notes on the identity of A. mitriformis, Phytotaxa 700 (2), pp. 223-232 : 225-228

Aloe perfoliata Linnaeus (1753: 319) .

Type:—Of unknown origin. LINN 442.1 (lectotype, Herb. LINN), designated by Reynolds (1950: 89, caption of Fig. 69) ( Figs 1 and 2 ).

Summarised notes on the type of the name Aloe perfoliata :—The first effective lectotypification of the name A. perfoliata was by Reynolds (1950: 89), when he specifically referred to the LINN 442.1 specimen as “ type material” in the caption of figure 69, which is a reproduction of the specimen ( Jarvis 2007: 279). The earlier citation by Scopoli (1783: 127–128) of Plate 15 of Dillenius (1732: 18, t.15, fig. 16) was not an effective typification, because it was not associated with the term “ type ” or an equivalent term ( Turland et al. 2018: Art. 7.11). The illustrations that Scopoli (1783) cited were merely to indicate suitable illustrations for the medicinal plants treated in his work and were not intended as typifications ( Klopper et al. 2016).

The type specimen of A. perfoliata consists of a single inflorescence (or perhaps a single raceme from a branched inflorescence), with a few pendent flowers. The raceme is few-flowered and lax, with short pedicels, and is rather cylindrical. It is very different from the dense, many-flowered, capitate or corymb-like racemes with long pedicels of the concept of, and as lectotypified A. mitriformis nom . et typ. cons. prop. ( Klopper et al. 2025: in press). The lack of vegetative material or any additional information on the specimen further hampers identification and the possibility of equating it to an extant aloe.

Taxonomic notes:—The name A. perfoliata is variously interpreted, with, most recently, a suggestion having been made that the name applies to what has been known consistently as A. microstigma Salm-Reifferscheid-Dyck (1854: 6, § 26, f. 4) for more than 160 years ( Mottram 2013, see also Klopper et al. 2016). However, the true identity of A. perfoliata remains unknown and the name is applicable to an imperfectly known taxon ( Reynolds 1950, Klopper et al. 2016). A proposal to conserve the name A. microstigma against the name A. perfoliata is under consideration ( Klopper et al. 2025: in press).

2. The nomenclature of A. mitriformis resolves as follows:

Aloe mitriformis Miller (1768 : first page headed “ALO | ALO”, No. 1), nom. illeg., but its use here retained under Turland et al. (2018: Rec. 14A.1) (nom. cons. prop., in Klopper et al. 2025: in press) ( Figs 3–5 ).

Type:—Plate published in Dillenius (1732: Fig. 19, t. 17) (typ. cons. prop., in Klopper et al. 2025: in press).

Summarised notes on the type of the name Aloe mitriformis :—The proposed designation by Glen & Hardy (2000: 100) of the plate that was published in Dillenius (1732), as Fig. 19, t. 17, as “ Iconotype ”—what they meant was ‘lectotype’—was not an effective typification of the name A. mitriformis . At any rate, although it might appear that the plate is the only element cited under the name A. mitriformis in Miller (1768: first page headed “ALO | ALO”, No. 1), the name A. mitriformis is homotypic with the name A. perfoliata . In addition, there is evidence that the plate published in Dillenius (1732: Fig. 19, t. 17) was not the only material that Miller used. In fact, Miller (1768), on later pages headed “ALO | ALO”, provides notes on the cultivation and characters of A. mitriformis , which is an indication that he indeed had further material of the species available to him.

In addition to the not effective typification of the name A. mitriformis by Glen & Hardy (2000: 100), a further, redundant, not effective re-typification of the name A. mitriformis by Mottram (2021: 15) with an: “Image reference RS [Royal Society]-10971, of a plant with inflorescence, captioned as Aloe africana , caulescens, folio crasso, obscuri viridi, spinis ad latera & in dorso armato. Boerh. Ind. Alt. Ii: 131, executed after 1735 by Georg Dionysius Ehret, with pencil plate number 10” was recently published. Neither the typification of Glen & Hardy (2000: 100) nor that of Mottram (2021: 15) can stand. Furthermore, no indication could be found that Miller (1768) used the Ehret plate mentioned by Mottram (2021: 15) when he [Miller] published the name A. mitriformis .

Taxonomic notes:—The name A. mitriformis , in the vernacular known as the mitre aloe, is in use for a distinctive, robust species that occurs naturally in the southwestern and northwestern parts of the Western Cape and southern part of the Northern Cape provinces of South Africa where a Mediterranean-type climate (warm to hot, dry summers and mild, wet winters) is prevalent ( Van Wyk & Smith 2014: map on p. 134, Smith et al. 2023: 41–43, 47) ( Fig. 4 ). Because of its predilection for growing in Mediterranean climates, the species had been introduced into parts of Europe with this climate ( Smith et al. 2023: 41–43, 47), and this is the reason why it was included in volume 5 of Flora europaea ( Webb 1980) , where the description provided coincides with the taxon that had been known as A. mitriformis .

Plants of A. mitrifromis develop long, robust stems that remain erect to leaning for a short period before they become creeping. Material of this species has capitate racemes and the flowers are carried on long pedicels ( Fig. 5 ).

Figures

FIGURE 1. The specimen LINN 442.1 held in Herb. LINN, which is of unknown provenance, is the lectotype of the name Aloe perfoliata. This typification was enacted by Reynolds (1950: 89, caption of Fig. 69) (see Fig. 2). The image is reproduced here with the permission of the Linnean Society of London, granted through Andrea Deneau, Digital Assets Manager of the Society.

FIGURE 2. In the caption of Fig. 69, Reynolds (1950: 89) unambiguously referred to the specimen LINN 442.1 as “[…] type material […]”, so typifying the name Aloe perfoliata on this specimen. This is the first effective lectotypification of the name A. perfoliata and must be followed (Turland et al. 2018: Art. 10.5). George Sherriffs, Library of the Royal Botanic Garden Edinburgh, Edinburgh, United Kingdom, is thanked for providing the image.

FIGURE 3. This plate published in Dillenius (1732: Fig. 19, t. 17) is the proposed conserved type of the name Aloe mitriformis. This plate is accessible at https://bibdigital.rjb.csic.es/viewer/10700/?offset=#page=45&viewer=picture&o=download&n=0&q=. Image courtesy of the Digital Library of the Royal Botanical Garden Madrid, Spain, CSIC (https://bibdigital.rjb.csic.es). Reproduced under Creative Commons 4.0 CC BY-NC-SA license.

FIGURE 4. Map of the natural geographical distribution range of Aloe mitriformis in the southwestern and northwestern parts of the Western Cape and southern part of the Northern Cape provinces of South Africa.

FIGURE 5. Aloe mitriformis is a summer-flowering species, here growing near the Gifberg in the northern part of the Western Cape province. The inflorescence is a dense, many-flowered, capitate raceme, with the flowers carried on long pedicels. Photograph: Hester M. Steyn.