Vanilla Miller (1754

Vanilla Miller (1754 View in CoL : without page number), nom. cons. prop.

Type species:— Vanilla planifolia Andrews (1808: 538) View in CoL , typ. cons. prop. ( Karremans & Pupulin 2023).

Etymology:—Latinized form of the Spanish vainilla, meaning small vaina, a tight-fitting holster for knives or swords, most likely in allusion to the shape of the fruit.

Replaced lectotype:— Vanilla mexicana Miller (1768 : without page number).

= Vanillophorum Necker (1790: 134) View in CoL , nom. inval., opus utique oppr.

= Myrobroma Salisbury (1807 View in CoL : t. 82).

Type species:— Myrobroma fragrans Salisbury (1807 View in CoL : t. 82), nom. illeg. = Epidendrum rubrum Lamarck (1783: 178) View in CoL = Vanilla rubra (Lam.) Urban (1920: 157) View in CoL .

= Dictyophyllaria Garay (1986: 231) View in CoL .

Type species:— Dictyophyllaria dietschiana (Edwall) Garay (1986: 231) View in CoL = Vanilla dietschiana Edwall (1903: 192) View in CoL .

= Miguelia Averyanov (2011: 45) View in CoL .

Type species:— Miguelia somae (Hayata) Averyanov (2011: 49) View in CoL = Vanilla somae Hayata, Icon. Pl. Formosan. View in CoL 6: 88. 1916.

Description:—Nomadic, epiphytic, lithophytic or terrestrial, herbaceous vines, usually germinating in decomposing organic matter or humus rich soil. Plants typically notoriously dimorphic. Plantlets erect, producing running horizontal stems, often with scale-like leaves, that locate phorophytes or other tutors by means of negative phototropism. Hosts not specific, with apparent exceptions. Mature stems scandent, zigzagy, sparsely or profusely branched, terete or quadrangular, sometimes sulcate, slender to thick, brittle to succulent, smooth to warty, up to 20 or more meters in length, typically erect when mature, reaching the apex of the host, then horizontal and pendent, often transitioning between these; mature stems able to reach the ground again and transforming into horizontal runners with scale-like leaves until climbing on a new tutor. Leaves and stems of runners and new growths often covered by a removable, glaucous wax, that is sometimes retained in mature plants. Roots of three kinds; the first are terrestrial roots found only at the base of the stem, thick, terete, and villose when in soil; the second kind short, usually flattened, slender and smooth, produced at each node, growing perpendicular to the stem and used to clasp the tutor; the third kind are elongate, mostly aerial roots, produced by nomadic vines and originating along the stem nodes, growing downwards parallel to the stem until they reestablish the connection with the ground, especially when the stem is severed. Leaves non-articulate, distichous, mostly with well-developed blades, in several species retaining the scale-like leaves typical of juvenile growths or mature runners, which are often deciduous; sessile to petiolate, the blades narrowly lanceolate to oblong or elliptic, soft-membranaceous to thick coriaceous. Inflorescence mainly axillary, rarely apical, racemose, sometimes branched, congested or scant, short or elongate, acropetalous, with two to a few dozen flowers, usually a single flower open at a time; bearing short or large floral bracts, either similar or quite distinct to the vegetative axis. Floral bracts often small, scale-like, at times foliaceous. Ovary articulate to the perianth, sulcate, smooth, rarely granulose, unilocular, rarely provided with an inconspicuous calyculus, typically incurved, straightening a few days after fecundation and becoming recurved after that. Perianth deciduous after a few days except when the flowers are fertilized, then retained longer. Extrafloral nectar produced from the floral bracts and calyculate apex of the ovaries of certain species. Flowers usually showy, short-lived, lasting from a few hours to a few days; sepals and petals usually green, yellow, cream or white, the lip usually similar in color, often stained with pink, red or purple; produced in acropetalous succession, mostly gullet-shaped, resupinate, mostly with horizontal or sub-pendular orientation, with the perianth deciduous, sometimes strongly fragrant, mostly nectarless. Sepals free, spreading, flat to contorted and undulate, membranaceous to fleshy, usually smooth, apex sometimes thick, granulose or warty. Petals free, often dorsally keeled, spreading, reflexed or undulate-contorted, margins mostly straight, occasionally minutely serrulate apically. Lip diversely fused to the column margins, merely at the base to almost completely to the apex, forming an open, deeply saccate or funnel-shaped chamber, in most species with a narrow, papillose-hirsute, dry, basal nectary formed by the fusion of the column and the lip’s claw; the lip blade simple to variously lobed, usually long-clawed, disc with longitudinal keels, trichomes, warts or thickened-rugose veins, often with a penicillate callus formed by a cluster of fimbriate, retrorse scales, placed below the column apex. Column semiterete, straight, sigmoid or arcuate, glabrous to pubescent on the ventral surface, sometimes with basal keels, mostly footless, provided with apical, more or less developed, thin to thick wings. Stigma forming a transversely rectangular to transversely elliptic slit-like cavity with thickened, sticky margins, or more often enclosed and completely hidden between the apical, flap-like, rostellar lobe and a stigmatic basal lobe exerting into a recurved flap. Anther versatile, terminal, semi-erect, incumbent to ventral, non-articulate, often subtended by a distinct, transversely rectangular, flat filament remnant; connective conspicuous, sometimes with horn-like projections formed by the incumbent twist of the anther. Pollen in monads, forming two or four, easily disrupted masses, without accessory structures, but sticky and sometimes removed as a triangular unit. Fruit mostly a dehiscent capsule to slightly dehiscent berry, sometimes indehiscent, usually opening along two lines and forming unequal valves, mostly fragrant. Seeds small, obovoid, black, with a sclerotic, crustose seed coat, surface smooth to slightly warty.

The previous description is based on that of Soto Arenas (2003), significantly modified and expanded to include detailed personal observations by the authors. It is important to note that many characteristics of Vanilla plants and flowers are often neglected or misinterpreted in literature, and require further attention. It is rarely noted where plants germinate, whether or not their stems, leaves and roots are dimorphic and ornate in any way, if the inflorescence are axillary or terminal and arise from erect, horizontal or pendent stems, if extrafloral nectar and floral fragrances are produced, or if the fruits are naturally dehiscent or not, and if they are truly non-aromatic. Plants are often described as hemiepiphytes, which they are not. They are typically nomadic vines (but see exceptions cited below), usually germinating on the ground and then becoming climbers that don’t lose the connection to the soil or do so only temporarily. The inflorescence has been described as cymose or paniculate in some cases, but the illustrative and photographic evidence is inconclusive (see discussion below). The flowers of the relatives of V. planifolia have a well-developed nectary formed by the fusion of the claw of the lip and the column base. The nectary has plenty of papillae and trichomes, and may offer traces of exudates, but is often dry, and usually does not seem to elicit continued consumption and visitation by any animals. There seem to be few exceptions, the most notable is V. hartii Rolfe (1899: 133) , which has measurable quantities of sweet nectar stored in an accordingly bloated nectary. Unlike most orchids, Vanilla flowers don’t have a true anther cap, but rather a versatile, flexible and quasi-ventral anther, nor do they have pollinia or a pollinarium, but rather loose masses of pollen monads. Fruits are often said to be non-aromatic when lacking the characteristic vanilla smell, but we have yet to find a Vanilla fruit that truly has no odor at all. Most, if not all, have a smell, albeit not always particularly strong or appealing. More careful characterization and documentation of the ecological, vegetative and flower features of Vanilla would be most useful.

Typification:—Upon publishing the name Vanilla, Miller (1754) did not select a type species. He included three species concepts detailed as “1. Vanilla flore viridi & albo, fructu nigrescente ”, “2. Vanilla flore violaceo , fructu breviori rubro ” and “3. Vanilla flore albo , fructu breviori corallino ”. Of the first he noted that “The Fruit of these Plants is call’d by the Spaniards, in America, Vanilla , or Vinello; and is much used by them to scent their Chocolate. It is the first Species here mention’d, which is chiefly esteem’d. This grows plentifully in the Bay of Campechy, in the West-Indies; where they are usually sold for about Three-pence each Fruit, English Money”. He would later formally name this species of commerce Vanilla mexicana Miller (1768) . Mansfeld (1959) typified the generic name Vanilla with V. mexicana , which he considered, at least in part, to be a synonym of V. planifolia Andrews (1808) .

The typification of the name Vanilla mexicana itself has long been unclear. In the protologue of V. mexicana, Miller (1768) cited a single element (“ Volubilis siliquosa Mexicana , plantaginis folio. Cat. Car. 3. p. 7”) referring to an illustration published by Catesby (1747). Although not explicitly stated, Catesby’s illustration is without a doubt based on those of Plumier (1703), the originals of which are kept at the Muséum National d’Histoire Naturelle in Paris (reproduced in Karremans et al. 2020). Despite its specific epithet chosen by Miller, the plant depicted by Plumier and reproduced by Catesby was not of Mexican origin, but from Haiti. Careful inspection by Soto Arenas & Dressler (2010) revealed that the illustration reproduced by Catesby is not the species of Vanilla that was cultivated in Mexico and much used by the Spaniards to scent their chocolate, as early authors such as Miller believed. In fact, not only is the Antillean taxon not known to occur in Mexico, it is not in cultivation on account of its non-aromatic fruits ( Soto Arenas & Cribb 2010; Karremans et al. 2020), but the two are now known to belong to separate subgenera and be quite distantly related ( Bouétard et al. 2010). As clearly stated in the protologue, Miller had the aromatic, cultivated species in mind when describing Vanilla mexicana , mistakenly believing it was the same species illustrated by Plumier, and reproduced by Catesby. Given that Miller did not cite any other material under V. mexicana we must select the illustration by Catesby as the type for the name. However, Karremans & Pupulin (2023) put forward a formal proposal to conserve the generic name Vanilla with a conserved type, replacing the non-aromatic V. mexicana for the well-known, widespread, commercially cultivated, aromatic V. planifolia Andrews as generitypus. This proposal, recommended by the Nomenclature Committee for Vascular Plants ( Applequist 2024) and accepted by the General Committee at the XX International Botanical Congress ( Wilson 2025), not only reflects the original intent of Miller, but also prevents any future attempt to segregate the aromatic species of Vanilla from the genus. However, it has the unintended consequence that the subgeneric names Vanilla subgen. Vanilla and Vanilla subgen. Xanata become synonyms as they are both typified by V. planifolia .

The authority of the generic name Vanilla is often incorrectly ascribed to Plumier in literature. The names ‘Vanilla’, ‘Vanillia’ or ‘Vaynilla’ had indeed been used prior to Miller’s formal publication in 1754. In 1703, Charles Plumier used the name as part of a polynomials to refer to species belonging to the genus. But these are all prior to the starting date for binomial botanical nomenclature in 1753. Genus Vanilla was validly published by Miller without any ascription to Plumier, or any other author, which means that their inclusion in the authority is taxonomically incorrect. To prevent arguments alleging that Art. 46.8 ( Turland et al. 2018) provides that ascription of a name is to be accepted when indicated by typographical or stylistic distinctions in the text, such as the diagnosis of Vanilla published by Miller - which is written in cursive -, it must be noted that this specific typographic style is used throughout the entire text ( Miller 1754) in the description of Miller’s own new genera. While it is true that starting with the seventh and all subsequent editions of his Dictionaire, Miller (1759) ascribed the name Vanilla to Plumier, Art. 46.8 ( Turland et al. 2018) also states that in determining the correct author citation, “only internal evidence in the publication as a whole” must be used, while Art. 46.9 ( Turland et al. 2018) is emphatic in that the use of external evidence to determine authorship of nomenclatural novelties included in a publication is advisable only “where there is no internal evidence of authorship”. Exactly the same occurs with the generic name Ceiba Miller (1754 : without page number), which had also been used previously by Plumier, but cannot be formally ascribed to the latter.

Finally, another element of debate is the etymology of the specific epithet “ planifolia ” when used in Vanilla , provided that the flat leaves are a rather standard feature among members of the genus. Although not explicitly stated by Andrews, when historical elements are taken into account it becomes evident that the flat leaves to which the author alludes are the sepals and petals of the flower. In the protologue, Andrews mentions that his species has been confused with that of Plumier’s first species ( V. mexicana Miller ), stating that “seldom seen two species of one genus so different in the blossoms”. Both Plumier (1703) and Miller (1754) describe this plant as having “an anomalous flower, consisting of six leaves”, and indeed V. mexicana is readily recognized by the notoriously twisted, undulate sepals and petals, which easily distinguishes it from V. planifolia , which has flat sepals and petals.