Ipomoea ramulosa

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

330. Ipomoea ramulosa J.R.I. Wood & Scotland, sp. nov

urn:lsid:ipni.org:names:

Type.

MEXICO. Guerrero. Agua de Obispo, 745 m, 31 Dec. 1965, Kruse 964 (Holotype MEXU74987).

Diagnosis. Probably related to Ipomoea costellata and its allies because of its lobed leaves and aristate sepals but very distinct because of the winged stem, deeply 3-lobed leaves, the much-branched, almost paniculate inflorescence, the white corolla with stamens held at the corolla mouth.

Description.

Completely glabrous climbing perennial; stems 5-6 m long, stout, slightly winged, reddish Brown. Leaves petiolate, 3.5-7 × 5-10 cm, 3-lobed, the central lobe broadly to narrowly oblong-elliptic, narrowed at both ends, acuminate, mucronate, the mucro 2 mm long, lateral lobes shallowly lobed or, near base, bilobed, the upper lobe forward-pointing, the lower lobe spreading, base broadly cordate, margin entire, abaxially paler; petioles 4-5.5 cm. Inflorescence of lax, compound, long-pedunculate, axillary cymes; peduncles 11-14 cm; bracteoles 1 mm, deltoid; secondary and subsequent peduncles 3-4.5 cm; pedicels 1-2.3 cm; sepals unequal, oblong-elliptic, terminating in a fine aristate point, the arista 2-3 mm long; outer 13-15 × 6 mm, the inner slightly longer and broader with broad scarious margins; corolla 6-6.5 cm long, funnel-shaped, white with tube yellowish-green inside, glabrous, the stamens held at the corolla mouth; stigma biglobose. Capsules and seeds unknown.

Illustration.

Figure 158 .

Distribution.

Endemic to Guerrero in Mexico, growing in a damp gully on alluvial soil at 745 m.

MEXICO. Guerrero. Type collection.

Note.

A very distinctive species because of the winged stem, deeply 3-lobed leaves, much-branched, almost paniculate inflorescence and the aristate sepals. The white flowers are reported to be aromatic. Molecular sequencing using ITS suggests a relationship with Ipomoea costellata and its allies but there is little superficial morphological similiarity apart from the aristate sepals and trilobed leaves.

Figures

Figure 158. Ipomoea ramulosa A habit B outer sepal C inner sepal. Drawn by Rosemary Wise from Kruse 964.