Ipomoea argentinica Peter

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

69. Ipomoea argentinica Peter , Nat. Pflanzenfam.4 (3a): 30. 1897 [pub.1891]. (Peter 1891: 30)

Mouroucoa juramenti Kuntze , Revis. Gen. Pl. 3 (2): 217. 1898. (Kuntze 1898: 217). Type. ARGENTINA. Salta, pasaje del Río Juramento, Lorentz & Hieronymus 285 (holotype B†, isotypes GOET, CORD, S, US).

Argyreia juramenti (Kuntze) K. Schum., Bot. Jahrsber. (Just) 26 (1): 382. 1900. (Schumann 1900: 382)

Ipomoea juramenti (Kuntze) O'Donell , Lilloa 14: 177. 1948. ( O’Donell 1948a: 177).

Ipomoea lorentzii Kuntze, Revis. Gen. pl. 3(2): 217. 1898. (Kuntze 1898: 217), nom. illeg. superfl. Type. As for Murucoa juramenti Kuntze

Type.

ARGENTINA. Salta, pasaje del Río Juramento, Lorentz & Hieronymus 285 (lectotype GOET 005548, designated by O’Donell (1959b: 110), isolectotype US).

Description.

Twining or, less commonly, trailing perennial, roots with small tubers, stems densely pubescent. Leaves petiolate, mostly 2-8 × 3-10 cm, broadly ovate to suborbicular, shallowly cordate to ± truncate with rounded auricles, apex acute and apiculate, adaxially green and appressed pilose, abaxially grey, tomentose with long, appressed hairs; petioles 1-8 cm. Inflorescence of compact pedunculate cymes; peduncles 4-7(-11) cm, usually grey-tomentellous; bracteoles 1.2-2 × 0.1-0.3 cm long, linear-lanceolate, long-acuminate, grey-tomentose, persistent; secondary peduncles 0.3-4 cm; pedicels 0-10 mm, often very short, tomentellous; sepals subequal, 9-10 × 4-5 mm, broadly lanceolate, acute to acuminate, silvery-sericeous, the inner ovate with scarious, glabrous margins; corolla 5-7 cm long, pale pink, adpressed-pilose, funnel-shaped, limb 3-4 cm diam., undulate to very shallowly lobed. Capsules ovoid, 8-9 × 7 mm, glabrous; seeds 6-7 mm long, long-pilose.

Illustration.

Figure 47J-P; O 'Donell (1959b: 111).

Distribution.

A species of the western Chaco in northern Argentina, western Paraguay and southern Bolivia. It is a lowland species of roadsides and disturbed bushy habitats, not found above 600 m. It is particularly common around the city of Santa Cruz in Bolivia. We have not traced the record from Brazil (Austin and Huáman 1996), which seems improbable.

ARGENTINA. Jujuy: H.H. Bartlett 20301 (SI, US); A. Krapovickas & A. Schinini 30639 (CTES). Salta: Cabrera et al. 34479 (SI); B.B. Simpson s.n. [20/1/1986] (MO).

PARAGUAY. Alto Paraguay: Perez de Molas & G. Navarro 9092 (CTES). Boquerón: Picada Sirascuas, F. Mereles & R. Degen 5476 (FCQ, MO); D.R. Brunner 1559 (G, MO, PY); L. Bernardi 20268 (G).

BOLIVIA. Santa Cruz: Chiquitos, Tres Cruces, J.R.I. Wood & B. Williams 27908 (OXF, K, LPB, USZ); Cordillera, A. Fuentes 2869 (USZ); Florida, La Angostura, J.R.I. Wood et al. 24101 (K, LPB, UB, USZ); Ibañez, M. Nee 49033 (CTES, LPB, MO, NY, OXF, USZ); Ichilo, J. Steinbach 1272 (LIL); Sara, La Bélgica, M. Nee & M.A. Sundue 52222 (LPB, NY, MO, USZ); Velasco, Santa Rosa de la Roca, J.R.I. Wood et al . 27791 (OXF, K, LPB, USZ). Tarija: Gran Chaco. Abrahamczck s.n. (LPB).

Note.

Distinguished from all similar species ( Ipomoea hieronymi , I. longibarbis , I. megapotamica ) by the very long bracteoles, which persist till corollas have fallen, those immediately below the calyx being particularly persistent. Additionally from I. longibarbis it can be separated by the adpressed, ± sericeous hairs of the sepals and from I. hieronymi by the more acuminate sepals. It has been treated as a synonym of the Brazilian Ipomoea sericophylla (Staples et al. 2012: 674) but differs in the much longer, persistent bracteoles, much less dense abaxial leaf indumentum and longer sepals.

Figures

Figure 47. A-H Ipomoea longibarbis. A habit B abaxial leaf surface C bracteole D outer sepal E inner sepal F section of corolla showing 3 stamens, ovary and style G fruiting inflorescence H seed. J-P Ipomoea argentinica J inflorescence K abaxial leaf surface L bracteole M outer sepal N inner sepal P ovary and style. Drawn by Rosemary Wise A-F from Nee & Linneo 54148; G, H from Killeen et al. 4199; J-P from Wood & Mamani 27502.