A foundation monograph of Ipomoea (Convolvulaceae) in the New World
Author
Wood, John R. I.
Author
Munoz-Rodriguez, Pablo
Author
Williams, Bethany R. M.
Author
Scotland, Robert W.
text
PhytoKeys
2020
143
1
823
http://dx.doi.org/10.3897/phytokeys.143.32821
journal article
http://dx.doi.org/10.3897/phytokeys.143.32821
1314-2003-143-1
F6F11A6EE4FF5A1885CEA2B60AE965A5
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
x
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
x
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
.
Figure 158.
Ipomoea ramulosa
A
habit
B
outer sepal
C
inner sepal. Drawn by Rosemary Wise from
Kruse
964.
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.