Ipomoea dumosa (Benth.) L.O. Williams

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

291. Ipomoea dumosa (Benth.) L.O. Williams , Fieldiana, Bot. 32: 190. 1970. (Williams 1970a: 190)

Exogonium dumosum Benth. , Pl. Hartw. 46. 1840. (Bentham 1839-57: 46). Type. MEXICO. Hidalgo, San Cornelia, K.T. Hartweg s.n. (lectotype K000612761, designated by Williams (1970b: 190), isolectotypes K, LD).

Calonyction galeottii M. Martens , Bull. Acad. Roy. Sci. Bruxelles 12: 268. 1845. (Martens and Galeotti 1845: 268). Type. MEXICO. Veracruz, H. Galeotti 1355 (holotype BR00006972615, isotypes BR, G, K, P).

Ipomoea purga auct.

Type.

Based on Exogonium dumosum Benth.

Description.

Climbing perennial herb to 5 m with fibrous roots, stems glabrous, relatively slender, wiry. Leaves usually very shortly petiolate, 4-10 × 2-6 cm, ovate, acuminate to an obtuse mucronate apex, base cordate with rounded auricles and narrow sinus, thin in texture, glabrous, abaxial veins prominent, usually glabrous, occasionally puberulent; petioles 2-6(-50) mm long, puberulent or glabrous. Inflorescence of very shortly pedunculate, 1-5-flowered axillary cymes, the base often enveloped by the leaves; peduncles 0.2-4 cm, often briefly fused to the petiole and penetrating the leaf sinus, shortly pilose or glabrous; bracteoles 1-2 mm, ovate, caducous; pedicels 3-15 mm, glabrous or thinly and very shortly pilose; sepals unequal, glabrous with white scarious margins, outer 3-5 × 3 mm, oblong-ovate, obtuse and mucronate, inner 8-12 mm, oblong-lanceolate, mucronate; corolla 5-7 cm long, glabrous, hypocrateriform with subcylindrical tube 4.5-6 cm long, slightly widening upwards, limb 3.5-4.5 cm diam., unlobed, deep reddish-purple to red, stamens exserted. Capsules 12-14 × 7-8 mm, conical, glabrous; seeds 4-5 × 4 mm, puberulent.

Illustration.

McDonald (1994: 41); Figures 10E , 142 .

Distribution.

Widely distributed from Panama through Central America north to central Mexico. It is found at altitudes below about 1300 m in various kinds of disturbed and natural woodland but often in rather moist areas of otherwise dry woodland. The two records from Brazil are anomalous but appear correctly named.

BRAZIL. Goiás: A. St. Hilaire 778 (P). Paraná: Sete Quedas/ Guaíra, Buttura s.n. (MBM74804).

PANAMA. Chiriqui, W.H. Lewis et al. 729 (MO).

COSTA RICA. San José, El General, A.F. Skutch 2270 (K, NY, MO, US); Tucurrique, A. Tonduz 12854 (BM); Wall 31 (S); Puntarenas, Coto Brus, M.M. Chavarria 688 (K, MO).

NICARAGUA. W.D. Stevens et al. 29321 (MO)

HONDURAS. Copán, L.O. Williams et al. 43009 (BM, F); A. Molina & A.R. Molina 24606 (F, MO, US).

EL SALVADOR. Hartman 98 (S)

GUATEMALA. Esquintla, San Luis, J. Donnell Smith 2014 (K); A. Molina & A.R. Molina 25372 (F, MO); Kellermam 5140 (MEXU, US); Santa Rosa, Heyde & Lux 4353 (BM, K); L. Rodríguez 1439 (P).

MEXICO. Chiapas: D.E. Breedlove & R.F. Thorne 20949 (MO). Colima: foothills of Vulcan de Colima, A.C. Sanders et al. 10418 (MEXU). Est. México & Dist. Fed.: Temascaltepec, G.B. Hinton 479 (BM, GBH); ibid., G.B. Hinton 2220 (BM, K, NY US); ibid., G.B. Hinton 4810 (K); ibid., San Lucas, G.B. Hinton 8594 (K); ibid., G.B. Hinton 11207 (K). Guerrero: G.B. Hinton 9479 (K); Mina, G.B. Hinton 9637 (K, NY, US); Montes de Oca, G.B. Hinton 11770 (K), Zitacuaro, G.B. Hinton 13427 (K). Jalisco: E. Palmer 373 (BM, MO); Jalpa, E.W. Nelson 4022 (K, US). Michoacán: L. Rowntree 246 (ARIZ); Zitácuaro, El Tizate, Y. Ramírez & V.W. Steinmann 490 (ARIZ, IEB); Charo, E. Carranza & I. Silva 6780 (IEB). Oaxaca: Choapam, Y. Mexia 9173 (K, MO, S); San Juan Bautista Tuxtepec, A. Flores 1019 (IEB). Puebla: Fröderström & Hultén 870 (S); Hueytamalco, Las Margaritas, G. Cornejo Tenorio 2764 (IEB); ibid., B. & G. Gómez 374 (K, MEXU, MO). Puebla: Hueytamalco, B. & G. Gómez 374 (MO). Querétaro: Landa de Matamoros, J. Rzedowski 54119 (IEB). San Luis Potosí: Tamazunchale, D.B. Dunn et al. 17534 (MO). Sonora: San Pedro Nolasco Island, C. Jurgensen 553 (BM). Veracruz: Valle de Córdoba, E. Bourgeau 1730 (K, P); ibid., E. Kerber 40 (BM, K); Orizaba, M. Botteri 561 (BM, K); C. Hernández et al. 222 (F).

Notes.

Ipomoea dumosa is usually recognised easily by the short peduncle which is enclosed in the folded leaf combined with the hypocrateriform corolla and exserted stamens.

The two records from Brazil are anomalous but the specimens appear correctly named. There is no evidence that Ipomoea dumosa is cultivated and it is unlikely that the labels were wrongly attached, especially in the case of the collection from Sete Quedas. Unfortunately this site has been flooded as a result of the construction of the Itaipú Dam so this species is presumably extinct in this site.

Ipomoea dumosa has rather distinct pollen (Figure 10E ), the spines being blunt and genmmiform as in species from the Calonyction Clade.

Ipomoea dumosa is the best known species in a complex of partially intergrading species. Ipomoea seducta is only distinguished by its funnel-shaped corolla and some specimens from Guerrero, Michoacán and Estado Mexico, are rather arbitrarily placed in one or other of these species. Ipomoea tubulata is only separated by the distinctly lobed corolla with short, ovate-deltoid lobes but some specimens from Michoacán are intermediate in character.

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 142. Ipomoea dumosa. A habit B habit showing fused petiole and peduncle C habit showing peduncle penetrating leaf sinus D adaxial leaf surface E abaxial leaf surface F outer sepal G inner sepal. Drawn by Rosemary Wise A, C-G from Hinton 9479; B from Hinton 11207.