Misapplied names, synonyms and new species of Ipomoea (Convolvulaceae) from South America

The identities of plants treated under the names Ipomoea goyazensis Gardner, I. bignonioides Sims, I. patula Choisy, I. fiebrigii Hassl. ex O’Donell, I. hirsutissima Gardner and I. carajasensis D. F. Austin are evaluated. It is shown that the name I. goyazensis should be used for the cerrado species often known under the name I. decora Meisn., rather than a plant from southern Brazil which is here described as a new species I. austrobrasiliensis J. R. I. Wood & Scotland. I. bignonioides Sims is synonymised with I. mauritiana Jacq., and an epitype is selected to fix the application of this name and ensure it is not confused with I. goyazensis. I. patula is lectotypified and treated as a synonym of the African I. crassipes Hook. The different recognised varieties of I. patula are evaluated; var. monticola Meisn. is treated as a species under the name I. langsdorffii Choisy; var. villosa Meisn. is shown to be a synonym of I. guaranitica Chodat & Hassl., in which is included the little-known species I. cornucopia Chodat & Hassl. Specimens from Paraguay, originally also treated as I. patula var. villosa or I. malvaeoides Meisn. var. ovata Hallier f., are treated as a distinct species named I. cordillerae J. R. I. Wood & Scotland. Plants from Brazil treated in various herbaria under the name of the Paraguayan species I. fiebrigii are shown to be a distinct species, which is described as new under the name I. angustissima J. R. I. Wood & Scotland. Species sometimes included in I. hirsutissima are discussed and a key to distinguish them is provided. I. pyrenea Taub. is illustrated and shown to be distinct and a plant from Paraguay sometimes named I. hirsutissima is described as new under the name I. megalantha J. R. I. Wood & Scotland. I. carajasensis D. F. Austin is shown to be a synonym of I. maurandioides Meisn. and plants from the cerrados of central Brazil often identified as this species are described as new under the name I. aequiloba J. R. I. Wood & Scotland. Two other commonly misunderstood species I. elegans A. Dietr. and I. serpens Meisn. are also discussed. All new species and some little-known species are illustrated, maps of contrasting distributions are provided and various lectotypifications are made to fix the concepts of several species discussed in this paper.


Introduction
During the course of our work in preparing a monograph of the genus Ipomoea L., we have become aware of a number of South American names which are misinterpreted in herbaria and the literature. This is partly a consequence of the near absence of taxonomic, as opposed to nomenclatural, publications on South American species since the series of papers published by O'Donell (1948O'Donell ( , 1950aO'Donell ( , 1950bO'Donell ( , 1952O'Donell ( , 1953O'Donell ( , 1959aO'Donell ( , 1959bO'Donell ( , 1960. Since then only the occasional paper describing new species has been published apart from the flora accounts prepared by Dan Austin for Ecuador (Austin 1982a), Venezuela (Austin 1982b) and the Guiana Highlands (Austin 1998). A recent paper by Austin et al. (2015) has formalised and compounded a number of these misinterpretations and this paper aims to clarify and correct the most important of these.

Materials and Methods
This paper is based primarily on the study of the relevant literature cited in the list of references and a range of specimens which we have seen in different herbaria in Brazil, the United States and Europe. We have made free use of type images and the reproductions of old, somewhat obscure publications available through Jstor (www.jstor.org/), which have proved very useful in the preparation of this paper. We have made regular use of other online data bases and their images, especially those of Tropicos (www.tropicos.org/), Reflora (www.herbariovirtualreflora.jbrj.gov.br/), neotropical herbarium specimens at the Field Museum (fm1.fieldmuseum.org/) and the New York Botanical Garden (sciweb.nybg.org/). We have consulted the Convolvulaceae in the Catalogus Hasslerianus (Ramella 2010) but draw readers' attention to the fact that the names in this catalogue are not necessarily published names but represent the names under which the plant is kept in the Geneva herbarium(Ramella2010:14).Ourcommentsandreasoning are set out under the headings of the main species we discuss.

The identity of Ipomoea goyazensis Gardner
There has been uncertainty about the application of this name for many years. The species was described by Gardner in 1842 but was included in Ipomoea batatoides Choisy as a synonym of I. batatoides var. angulata Choisy by Choisy (1845) in De Candolle's Prodromus. Meisner (1869) in Flora Brasiliensis, however, accepted I. goyazensis as a distinct species and included it within a group characterised as having "folia cordata, pedunculi brevissimi (saltem folio breviores), pauci -1-flori", in which he also described I. decora Meisn., thus implying they were different species. He did not, however, compare the two and no one seems to have done this over the next 80 years. However, in the 1950s it seems, from his herbarium determinations, that O'Donell had come to regard I. goyazensis and I. decora as conspecific and treated both under the older name I. goyazensis, an opinion with which we agree.
There is no dispute as to the identity of Ipomoea decora, of which there is a type specimen (Pohl s.n.) at K and OXF, and an illustration in Flora Brasiliensis. In recent years this name has generally been used for the cerrado species from central Brazil which is characterised by a compact inflorescence with very short peduncles and pedicels ( Fig. 1), whereas the name I. goyazensis has been applied to a quite different species from the Atlantic forest regions of southern Brazil characterised by a lax inflorescence with long peduncles and pedicels (Fig. 2). This interpretation appears to have arisen from Choisy's decision to unite I. goyazensis with I. batatoides var. angulata treating it as one of the syntypes of this variety. The other syntype, Martius s.n, (M0184900), clearly represents the species from the south of Brazil but the implication (Austin et al. 2015: 631, note 3) that Choisy's disposition of the specimens at Munich (M) is critical to the typification of I. goyazensis is erroneous. I. goyazensis was described by Gardner some two years earlier and Choisy's comments are only relevant to the typification of I. batatoides var. angulata.
The specimen cited as the type of Ipomoea goyazensis, Gardner 3909, could not be found at K, BM or OXF and may have been lost after the preparation of the plate in Hooker's Icones Plantarum so the only possible type is this image. This is quite clearly not the same as Martius s.n. at Munich, the type of I. batatoides var. angulata, but is a quite reasonable representation of the cerrado plant usually treated today as I. decora. This is confirmed by examination of the protologue which describes the peduncles as short, three-flowered and the corolla having a white tube but violet limb, exactly fitting the cerrado plant ( Fig. 1). Even more convincing is the type locality (Serra de Santa Brida) from northern Goiás around 12°30'S 47°15'W. This is well within the known range of this species but far from southern Brazil where I. batatoides var. angulata grows. (Map 1). We thus concur with O'Donell that I. goyazensis is the correct name for the plant often identified as I. decora and that a name at specific rank is required for I. batatoides var. angulata. The two species with their synonomy are set out below: Ipomoea goyazensis Gardner, Icon. Pl. 5: t. 479 (1842 its ability to colonise secondary bushland or ruderal habitats so for the time it should be classified as Data Deficient (DD). EPONYMY. The epithet austrobrasiliensis, meaning "south Brazilian," refers to the geographical region in which this species occurs.
Ipomoea bignonioides Sims Ipomoea bignonioides Sims was described by Sims (1826) in the Botanical Magazine from a plant cultivated in England from seeds said to have been collected in Cayenne (Guyane Française). It is clear from the protologue that no specimen was retained and so the only possible type is the illustration (Fig. 3). This is somewhat odd showing a brownish corolla colour we have never observed in Ipomoea, an inflorescence with a single flower and 3-lobed leaves. Both Choisy (1845) and Meisner (1869) accepted this as a good species but neither author cited any specimens under this name. In the 20 th century some herbarium annotations suggest it could be equated with I. blanchetii Choisy, perhaps because I. blanchetii has 3lobed leaves and similar coriaceous sepals, but I. blanchetii is a species of NE Brazil, not the Guyanas, and always has a branched inflorescence. In a recent paper Austin et al. (2015) treated this species as a synonym of Ipomoea goyazensis. This has to be an error on several counts. In the first place I. bignonioides is an older name and so should have been taken up in preference to I. goyazensis. More importantly, there is no good reason to believe the two species are conspecific. I. goyazensis has never been collected north of the Amazon (Map 1) and its occurrence in Cayenne is highly improbable. In any case, neither the leaf shape nor the inflorescence fit I. austrobrasiliensis, as I. goyazensis was interpreted in Austin et al. (2015), or I. goyazensis itself. More recently the Flora do Brasil 2020 em construção website when accessed on 19 April 2016, treated I. bignonioides as a distinct from I. goyazensis (as I. decora Meisn.) and showed a distribution restricted to NE Brazil south of the Amazon, far from Cayenne. The photograph on the website shows a plant with entire leaves and a cymose inflorescence very different from the type of I. bignonioides. Whether this plant is distinct from I. goyazensis is unclear but it cannot be equated with I. bignonioides.
It is, however, possible to infer the identity of Ipomoea bignonioides with some degree of certainty. Assuming its stated origin is correct, the only possible candidate species are I. mauritiana Jacq. and I. batatoides Choisy; both species occur in the Guyanas and both have the distinctive coriaceous sepals clearly visible in the illustration of I. bignonioides. I. batatoides is, however, very improbable as this species nearly always has unlobed leaves. Examination of material of I. mauritiana from the Guyanas reveals this species to be much the most probable candidate. One of the syntypes of Batatas edulis var. platanifolia Choisy (Schomburgk 701), a synonym of I. mauritiana, is represented at Kew by three sheets, one of which, K000768180 shows almost exactly the same inflorescence as the plate in the Botanical Magazine as well as 3-lobed and 5-lobed leaves (Fig. 4). In order to fix the identity of I. bignonioides we propose to select this specimen as an epitype of I. bignonoiodes, which we, therefore, treat as a synonym of I. mauritiana. It should be noted that the BM duplicate of Schomburgk 701 with the original label and the OXF duplicate are very similar to the epitype.

The identity of Ipomoea patula Choisy
There is some uncertainty about the application of this name, which has only occasionally been used for South American plants (Meisner 1869;Hallier 1899;Chodat & Hassler 1905 In order to maintain traditional usage, clarify the situation and, inouropinion,interprettheprotologuecorrectlyweare formally designating the specimen at Paris (P00434156) as the lectotype of Ipomoea patula. This specimen which constitutes the original material used by Choisy has no collector's name but is labelled "Brasilia", which is crossed out and relabelled in another hand "Guinea". The specimen actually represents an African plant, identified by Heine as I. crassipes Hook. There can be little doubt that Choisy's description refers to this specimen, rather than Martius 788, which in any case was never apparently housed at Paris, particularly the reference to dimorphic leaves (foliis superioribus oblong-lanceolatis acutis inferioribus ovatis obtusis 10 -12 lineas longis), the long peduncle exceeding the leaves (pedunculis foliis superantibus) and lanceolate bracteoles (bracteis lanceolatis..). In contrast in Martius 788 the leaves are all clearly similar, the lower leaves much longer than "10 -12 lineas" and not ovate, the peduncle is much shorter than the subtending leaves and the bracts (bracteoles) are clearly linear, not lanceolate. As the protolgueso clearly fitstheParisspecimen,originally labelled "Brasilia", Martius 788 should not be considered as a possible lectotype of I. patula. It does, however, constitute the type of I. monticola which we consider to be a synonym of I. langsdorffii Choisy. This is summarised below: Ipomoea crassipes Hook. (Hooker 1844: t. 4068 Dietr., as opposed to I. elegans Meisn., is a synonym of I. patula Choisy. As I. elegans A. Dietr. antedates I. patula by almost ten years it would appear that it should be instated as the correct name for the plant treated above as I. langsdorffii. We do not believe this to be the case. Dietrich (1836) diagnosed I. elegans as "foliis inferioribus, quinquelobis, superioribus palmatim-septemlobis utrinque subhirtis scabriusculis, lobis lanceolatis, obtusis …" None of these statements fit I. langsdorffii, which has simple hirsute leaves. As Dietrich mentions that the plant has been in cultivation for a long time, it seems most likely that I. elegans A. Dietr. is the earlier I. platensis Ker-Gawl, also described from cultivated material, or just possibly I. gigantea Silva Manso or I. malvaeoides Meisn.
Species treated as varieties of Ipomoea patula Choisy Meisner (1869) described two other varieties of Ipomoea patula, var. γ selloana and var. δ villosa, both from southern Brazil and both based on collections by Sello(w). We have not traced any possible type of var. γ selloana or any specimen that might be considered part of the original material seen by Meisner so this name remains of uncertain application. However, the pho-tograph of Sellow 5089 at the Field Museum, taken of the specimen at Berlin destroyed in 1943 and labelled "Ipomoea patula Chois. δ villosa Meisn." is of a syntype of var. δ villosa. In our opinion this is a good match with the plant subsequently described as I. guaranitica by Chodat & Hassler (1905). This was treated as a synonym of I. langsdorffii (under the name I. patula) by Austin et al. 2015 but this is clearly erroneous.
We are also taking the opportunity here to reduce Ipomoea cornucopia to synonymy with I. guaranitica. This species has been confused with I. pseudocalystegia Hassl. but examination of the two sheets at G shows it to be synonymous with I. guaranitica. The sheet without corollas is labelled as having been collected by the Río Capibary on the way to Yerbales in the Sierra de Maracayú, this last being the type location of I. guaranitica. On the sheet with corollas, the label does not mention Yerbales or the Sierra de Maracayú but there is descriptive information, curiously not used in the preparation of the protologue. As the description must have been based mostly on the flowering specimen, this is selected as the lectotype of I. cornucopia. The exact location of Río Capibary is unknown.
Balansa 1049 (G, P) differs from Hallier's description in several important ways, notably in having some leaves 3-lobed, and was, in  Hassler 6760 from Valenzuela has been distributed widely under the name Ipomoea malvaeoides var. ovata following Chodat & Hassler (1905: 690), but it represents another different species with shorter obtuse sepals, resembling but not conspecific with I. cerradoensis J. R. I.Wood & Scotland.

Ipomoea fiebrigii Hassl. ex O'Donell
Ipomoea fiebrigii is a little known and rarely collected species described by O'Donell (1948: 169) based on a name proposed by Hassler (1917: 18). As far as we know it has only ever been found in Alto Paraná Department in Paraguay and has only been collected on three occasions, the type collection from Ñucañy (Fiebrig 5675 [holotype LIL, isotypes SI, US]), a second collection by Fiebrig (Fiebrig 6706 from Ytaquiry, also at LIL) and a more recent collection, Itaipú Binacional 1081 (MO) from Reserva Tatí Yupí. Map 2. Fig. 8.
Plants from the planalto of Brazil, however, have commonly been identified as Ipomoea fiebrigii but on careful examination are clearly distinct. This Brazilian species is described as new below: Ipomoea angustissima J. R. I. Wood & Scotland,sp. nov. Type: Brazil,Goiás,16  Perennial herb to 40 cm from a tuberous rootstock, apparently unbranched or branched near the base only; stems erect, asperous-pubescent. Leaves sessile or very shortly petiolate, compound, 1 -7 leaflets radiating out from the base, segments 0.8 -5 × c. 0.1 -0.5 cm linear, acute, 1-veined, thinly pilose to ±glabrous; petioles 0 -2 mm, thinly pilose. Inflorescence terminal consisting of single flowers or compact few-flowered cymes from the uppermost leaf axils; peduncles 1 -9 mm, pubescent; bracteoles 3 × 1.5 -2 mm, oblong, rounded to retuse, thinly pubescent, margin scarious, caducous; pedicels 3 -7 mm, pubescent; sepals subequal, 5 -8 × 5 -6 mm, elliptic, obtuse to rounded, pubescent except for the scarious margins, outer sometimes mucronulate, reddish, margins narrow, inner more rounded with broader scarious margins; corolla 3.5 -4 cm long, funnel-shaped, pink, pubescent, limb c. 2.5 cm diam., somewhat lobed; stamens included; filaments glabrous except for pubescent bases, unequal, shorter 6 -7 mm, longer 9 -10 mm, anthers 2.5 -3 mm long; ovary glabrous, style 10 -11 mm long, glabrous. Capsule and seeds not seen. Fig. 9. RECOGNITION. Ipomoea angustissima differs from I. fiebrigii in the short, appressed, somewhat stiff hairs of the stem, leaves, sepals and corolla exterior. In I. fiebrigii the indumentum is of relatively long, soft, whitish hairs these being particularly prominent on the exterior of the corolla and the sepals (Fig. 8). Additionally the sepals of I. angustissima are ±rounded, 5 -8 mm in length, whereas those of I. fiebrigii are 9 -11 mm long, the outer narrowed to a truncate, mucronulate apex, the inner tapered to a subacute apex. In I. angustissima the inflorescence is often (but not always) subterminal and the inflorescence is formed of 1 -3-flowered cymes (Fig. 9A). In contrast I. fiebrigii has solitary axillary flowers (Fig. 8A). The upper part of the stem and peduncles of I. angustissima may be sticky as granules of sand stick to the hairs, the stem appearing superficially to be granulose. CONSERVATION STATUS. This species is restricted to two chapadas in central Brazil, both enjoying legal protection. We have no knowledge of its frequency in either location but it seems to be tolerably frequent in the Chapada de Veadeiros. Without further studies, this species must be classified as Data Deficient within IUCN (2012) guidelines. EPONYMY. The epithet angustissima, meaning very narrow, refers to the very narrow leaf segments.
Species confused with Ipomoea hirsutissima Gardner Ipomoea hirsutissima was described by Gardner based on his own collection from Goías. As with the cases of I. decora and I. elegans cited earlier, Meisner (1869) seems not to have seen species published by earlier botanists and went on to newly describe the same species under different names, thus both I. hirsutissima and I. chrysotricha Meisn. appear in Flora Brasiliensis. We agree with Austin et al. (2015) that these two represent the same species and that  the three specimens at Geneva. The full synonymy is set out below: Ipomoea hirsutissima is an erect species with a characteristic indumentum of long spreading rough hairs covering all vegetative parts as well as the exterior of the corolla. The hairs have bulbous bases which are often blackish as in the image in Wood et al. (2015: 40). The very acute to acuminate sepals about 12 -16 mm in length are also distinctive. I. hirsutissima is widely distributed in several localities in Bolivia, Brazil and Paraguay but is rarely collected and appears to be uncommon in all three countries. In Brazil most records are from Minas Gerais and it appears to be very rare elsewhere with only a handful of records from Goías, Mato Grosso, Mato Grosso do Sul (Dubs 1998: 76) and São Paulo.
Among Brazilian plants Ipomoea hirsutissima is only likely to be confused with I. aurifolia Dammer, which is similar in indumentum and facies but differs in having narrower, usually lanceolate leaves, rather than the oblong-elliptic to obovate leaves of I. hirsutissima. Additionally I. aurifolia has much shorter obtuse to subacute sepals. It appears to be restricted to the Distrito Federal around Brasilia and neighbouring parts of Goías. Inexplicably it was treated as a synonym of I. campestris Meisn. by Austin et al. (2015) but differs in its distinctive indumentum and shorter subacute sepals as set out in the key below.
Austin et al. (2015), did, however treat another species, Ipomoea pyrenea Taub. as a synonym of I. hirsutissima. We believe this was mistaken. I. pyrenea is a little-known species endemic to the Serra de Pireneus in Goías (Map 3). It has distinctive oblong leaves 2.5 -5 × 0.3 -0.7 cm and a subterminal inflorescence. The cymes are subsessile even below and the sepals are only 8 -11 mm in length. The leaves and stems are softly and thinly pubescent with appressed hairs, an indumentum quite different from that of I. hirsutissima. As this species is rare and localised we have provided an illustration (Fig. 10) and cited all the specimens we have seen below: A further species, from Paraguay, was originally identified as Ipomoea hirsutissima by Hassler and agrees with it in habit, indumentum, shortly petiolate leaves, persistent linear-lanceolate bracteoles, sepal shape and the usually solitary flowers. It differs however in the presence of some trifurcate leaves and the much larger corolla which is usually about 9 cm in length whereas in I. hirsutissima it is only 6 -7 cm long. O'Donell apparently regarded it as belonging to I. acutisepala O'Donell and in 1953 identified the isotype in SI as a "forma" of this species. However he did not cite Hassler 9114 when describing I. acutisepala (O'Donell 1950b)  http://www.ipni.org/urn:lsid:ipni.org:names:60473764-2 Perennial subshrub; root a woody xylopodium of unknown size but at least 2 cm thick and 8 cm long; stems decumbent or ascending, woody, pilose, glabrescent when old, 10 -40 cm long. Leaves shortly petiolate, 1.5 -9.5 × 0.5 -5 cm, oblong to ovate, obovate or elliptic, often trifurcate on the same plant, apex obtuse or acute, mucronate, base broadly to narrowly cuneate, margin entire, both surfaces pilose, more densely so on the veins; petioles 2 -9 mm, pilose. Inflorescence of solitary, axillary flowers arising from towards the base of the stem; peduncles 2.5 -6 cm, pilose; bracteoles 13 -27 × 1 -3 mm, linearlanceolate, pilose, persistent; pedicels 3 -11 mm, pilose; sepals slightly unequal, lanceolate, finely acuminate, outer 17 -20 × 3 -6 mm, abaxially pilose, inner up to 22 mm long, the central area pilose, the margins scarious, glabrous; corolla 8.5 -9.5 cm long, ±funnel-shaped, gradually widened from base, midpetaline bands densely pilose; limb 5 -6 cm diam., unlobed; stamens included, anthers glabrous except widened, hirsute basal part, longer c. 22 mm; shorter 13 -15 mm; style 20 -21 mm long, glabrous, stigma bilobed, subglobose; ovary glabrous. Capsule and seeds unknown. Fig. 11.
RECOGNITION. Ipomoea megalantha is distinct from all related species by its much larger corolla which is about 9 cm in length. It is similar in habit and indumentum to I. hirsutissima but is also distinguished by the presence of trifurcate leaves. I. acutisepala differs in its longer trailing stems, leaves with petioles 1 -3 cm long, the shorter, somewhat caducous bracteoles, the usually branched inflorescence, shorter sepals (13 -17 mm long) and shorter corolla. HABITAT & DISTRIBUTION. Only known from the Department of Caaguazú in Paraguay, where it grows in "campos" (fide Balansa and Jorgensen) or in cerrado   , 19 Oct. 1994, A. Krapovickas et al. 45769 (K). CONSERVATION STATUS. Ipomoea megalantha has been collected four times over 140 years so it is clearly very rare. We have no idea of the extent of original populations but it must be at risk from habitat destruction and the presence of invasive grass species of African origin. If, as is likely, this is a cerrado species, search should be made in the spring after fire has passed through any grasslands which survive. This species should be provisionally classified as Critically Endangered (CR) based on its very restricted, although undefined range, and the known vulnerability of its habitat. Field work is urgently needed to confirm its status and, as seems necessary, steps should be taken to secure the conservation of one of the most spectacularflowered species of Ipomoea. NOTES. In Paraguay Ipomoea megalantha is restricted to Caaguazú whereas I. hirsutissima appears to be restricted to the Sierra de Maracayú in Canindeyú Department (Hassler 5007) and Alto Paraná (G. Caballero 1184 at G). I. acutisepala was described from Argentina (Misiones) and extends into Santa Catarina and Paraná in Brazil but apparently not into Paraguay. Ipomoea maurandiodes is a quite variable species in leaf shape, indumentum and inflorescence. Leaves vary from lanceolate to ovate with rounded to acute auricles. Plants are usually glabrous but hirsute forms occur sporadically throughout most of its range and can be recognised as var. subtomentosa (O'Donell) J. R. I. Wood & Scotland. The inflorescence is commonly formed of solitary axillary flowers but is cymose in quite a few collections. However, the slender habit and very unequal, often prominently veined sepals with the inner sepals ovate, rounded to obtuse and mucronate make this species relatively distinct. Fig. 12.
Although O'Donell (1952: 242) pointed out that Ipomoea serpens Meisn. was not conspecific with I. maurandiodes and stated it to be "indudablemente" conspecific with a polymorphic I. asarifolia (Desr.) Roem. & Schult., this has often been ignored and the claim that I. serpens Meisn. is conspecific with I. maurandioides was repeated in Austin et al. (2015) and in the Flora do Brasil 2020 em construção website when accessed on 19 April 2016. I. serpens Meisn. is indeed related to I. asarifolia, rather than I. maurandioides but we believe it is distinct and have renamed it I. paludicola J. R. I. Wood & Scotland (Wood et al. 2015).
However, not all plants named Ipomoea carajasensis belong to I. maurandioides. In particular, plants with lanceolate, acuminate and mucronate sepals are clearly a distinct species. These are easily recognised by the distinctive oblong, sagittate leaves in which the two auricles are also oblong and resemble the main leaf blade, the leaf thus appearing 3-lobed. This is described below. unequal sepals and usually solitary, medium-sized pink flowers. From I. maurandioides the new species is distinguished by having always solitary flowers and all the sepals lanceolate and finely acuminate, rather than the inner sepals oblong-oblanceolate and mucronate as illustrated in O'Donell 1959b: 188. From I. mucronatoproducta it is distinguished by the midpetaline bands terminating in a small tooth rather than in a long fine point up to 6 mm in length. From both it is immediately distinguished by the distinctive, apparently 3-lobed leaves in which the two auricles are more or less equal with the blade.
HABITAT & DISTRIBUTION. A plant of the Brazilian cerrados extending into NE Argentina growing between 150 and 600 m. It has a very wide but very scattered distribution (Map 3) but there does not seem to be any significant difference between specimens collected in wide area of central Brazil from five different states and from Misiones Province in NE Argentina so it would appear to be of Least Concern, although records are not very numerous. However the cerrado biome is under threat from conversion to pasture, competition from invasive African grasses, soya cultivation and, in recent years, to the production of biofuels. As all records of Ipomoea aequiloba appear to be from low altitude, presumably vulnerable cerrados, the status of this species needs to be carefully evaluated to assess whether it is under any threat. For the moment it should be classified as Data Deficient (DD). EPONYMY. The epithet aequiloba refers to the apparently 3-lobed leaves in which the auricles equal the blade.