Ipomoea peruviana O'Donell

Wood, John R. I., Munoz-Rodriguez, Pablo, Williams, Bethany R. M. & Scotland, Robert W., 2020, A foundation monograph of Ipomoea (Convolvulaceae) in the New World, PhytoKeys 143, pp. 1-823 : 1

217. Ipomoea peruviana O'Donell , Bol. Soc. Peruana Bot. 1: 4 ( O’Donell 1948b: 4)

Ipomoea acrensis J.R.I. Wood & Scotland, Kew Bull. 72 (10): 2 (Wood and Scotland 2017b: 2). Type. BRAZIL. Acre, Mun. de Río Branco, Apa do Ireneu Derra, 12 July 2007, C. S. Pessoa, E. Consuelo, I.E.S. Moll, P. Palhares, Adriana, F. Obermüller, M. Silveira, I.M. Saar & W. Castro 302 (holotype RB501233).

Type.

PERU. Loreto, Balsapuerto, G. Klug 3089 (holotype S07-4771, isotypes BM, F, GH, K, MO, NY, US).

Description.

Twining perennial liana of unknown height; stems glabrous, somewhat woody. Leaves petiolate, 6-16 × 5-12 cm, ovate, shortly acuminate to a fine point, cordate, the auricles rounded or acute, margin undulate, sometimes 3-lobed to half way, often irregularly dentate, glabrous, paler beneath, thin in texture, main veins abaxially prominent; petioles 9.5-11 cm, glabrous. Inflorescence of up to 7-flowered, axillary, pedunculate compound cymes, glabrous; peduncles 12-15 cm, stout, woody; bracteoles not seen, caducous; secondary and tertiary peduncles c. 2.5 cm; pedicels 2.3-6.5 cm, conspicuously thickened upwards; sepals slightly unequal, outer 18-22 × 10-12 mm, narrowly oblong-elliptic, acute or obtuse, mucronate, inner sepals very slightly shorter, pale green; corolla c. 10-11 cm long, glabrous, pale blue, narrowly funnel-shaped, the tube 2-2.5 cm wide for 5-7 cm; limb 5-6 cm diam., apparently lobed. Capsules and seeds not seen.

Illustration.

Figures 108 , 190E .

Distribution.

Amazonian Peru and Bolivia and neighbouring Acre in Brazil. It appears to be scattered in disturbed tropical rainforest over a wide area but uncommon.

BRAZIL. Acre: type of Ipomoea acrensis .

BOLIVIA. Beni: Marbán, Puente San Pablo, M.T. Martinez & M. Adler 83 (K, LPB, USZ). Cochabamba: Carrasco, Valle de Sajta, J.R.I. Wood et al. 28915 (K, LPB, USZ).

PERU. Huánuco: Huallaga valley, A. Gentry et al. 37636 (FTG, MO, OXF, USM); J. Díaz in De La Puente 4290 (CIP, FTG). Loreto: type of Ipomoea peruviana . Madre de Dios: Tambopata, M. Alexiades & A. Byrne 865 (NY, OXF, USM). San Martín: G. Klug 4326 (LIL, S).

Notes.

All parts of this species are glabrous, the inflorescence long-pedunculate and up to 7-flowered. The leaves may be entire or 3-lobed and the corolla is a characteristic pale blue.

Wood et al. (2017d: 11) discussed how Ipomoea acrenis had been confused with material of I. cuscoensis and as the type of I. acrensis belongs to I. peruviana it is here included as a synonym of I. peruviana .

•• Clade A3 (Species 218-233) comprises the Batatas Clade and a single sister species, Ipomoea cryptica . Unlike Clades A1 and A2, about half the species are annuals and none are woody. The pollen is also somewhat different (Figure 10 A, B ) with relatively more echinulae.

• The Batatas Clade (Species 218-232) is an economically important clade containing the sweet potato and its crop wild relatives and is well supported in our 605 nuclear regions and chloroplast whole genome sequence data.

Annual or perennial herbs; stems trailing and rooting or twining, never woody. Leaves ovate, entire or 3-5-lobed but never divided into segments. Flowers in pedunculate cymes (only solitary by reduction), the pedicels commonly relatively short compared to the peduncles; bracteoles small, usually caducous; sepals equal or somewhat unequal, membranous, often chaffy in fruit, lanceolate or oblong to ovate or obovate, margins glabrous or ciliate, hyaline, the central vein prominent, laterals sometimes present; apex mucronate to caudate. Corolla relatively small (<5 cm long), campanulate or funnel-shaped, glabrous, white, pink or pale pink with a dark pink throat, the midpetaline bands often terminating in small teeth; stamens often rather short; filaments with basal hairs sometimes extending upwards; anthers included. Ovary and capsule glabrous or hirsute, 2-locular, 4-seeded; seeds glabrous or sparsely pubescent.

Based on their morphology several species including Ipomoea amnicola and I. cryptica might be interpreted as belonging to this clade but both differ in their pilose seeds, while the latter also has very unequal sepals, the outermost very short. As Ipomoea cryptica is, in fact, sister to the Batatas Clade it is included it in the following key.

Most species are poorly defined morphologically, although our extensive nuclear data retrieves most taxa as monophyletic. Plants intermediate morphologically are not uncommon and are difficult to assign to species so specimens misidentified even by experienced Ipomoea specialists are commonly found in most herbaria. Ipomoea cynanchifolia appears to be morphologically intermediate between I. ramosissima and I. grandifolia , occurring only within the range of the latter. Ipomoea grandifolia itself resembles a large-flowered form of I. triloba and appears to be intermediate between I. triloba and perhaps I. australis . Ipomoea leucantha appears to be an intermediate between I. cordatotriloba and I. lacunosa . Ipomoea tiliacea and I. littoralis are difficult to separate except on molecular or geographical grounds and I. tiliacea has frequently been recorded from the Old World, probably always erroneously. Records of I. littoralis from Mexico have been shown to be errors for I. batatas (McDonald and Austin 1990). Cultivated I. batatas is usually easily identified by its perennial habit, trailing stem which roots at the nodes, ciliate sepals and subumbellate cymes but wild populations can be very difficult to separate from I. tiliacea on the one hand or I. trifida on the other. Forms of Ipomoea batatas are fairly commonly misidentified as I. trifida (Austin 1982a: 41; Deroin 2001) and some “species”, I. confertiflora , for example, have been treated as belonging both to I. trifida and I. batatas . This is not entirely surprising as there is strong evidence that I. batatas has evolved from I. trifida ( Munoz-Rodriguez et al. 2018) .

Several species are more common near the sea or on islands, although not strictly maritime ( Ipomoea tiliacea , I. triloba and possibly I. tenuissima ). Ipomoea littoralis is the only truly maritime species although some forms of I. batatas ( var. apiculata ) occur on coastal sand dunes.

The species can be separated using the following key:

Figures

Figure 10. Pollen of Ipomoea species. A I. triloba (D'Arcy 317) B I. cryptica (Steinbach 6311) C I. purpurea (Parada & Rojas 2664) D I. alba (Wood et al. 27828) E I. dumosa (Hinton et al. 9479) F I. hederifolia (Queiroz 15975) G I. stans (Y. Mexia 275112) H I. suffulta (Pringle 4755). Photos by Robert Scotland.

Figure 108. Ipomoea peruviana. A habit B outer sepal C inner sepal D fruiting calyx. Drawn by Rosemary Wise A from Pessoa et al. 302; B, C from M. Alexiades & A. Byrne 865; D from A. Gentry et al. 37636.

Figure 190. Photographs of Ipomoea species. A I. tiliifolia B I. rubens C I. corymbosa D I. ochracea E I. peruviana F I. echinocalyx. A http: // tropical. theferns. info / B John Pink C John Wood D Starr Environmental E Maira Martinez F John Wood.