Ipomoea

Ipomoea L. (incl. Pharbitis Choisy, Quamoclit Mill.)

Ipomoea is a large genus of probably 600-700 species. Most are concentrated in warm-temperate regions and the (sub-) tropics, especially in the New World. Several species have become pantropical and troublesome agricultural weeds.

Modern taxonomists accept Ipomoea in a broad sense (Mabberley 2008). Segregate genera like Pharbitis and Quamoclit are poorly distinguished and better included in Ipomoea. However, in its traditional circumscription it is not monophyletic (e.g. Eserman & al. 2014).

Several species are grown as ornamentals in Europe (at least 16 according to Hyam 2000; see also Jäger & al. 2008) but, with the exception of Ipomoea tricolor, no exclusive garden escapes have been recorded in Belgium so far. Almost all species are introduced with grains or oilseeds.

1. Stem, leaves and flower stalks distinctly hairy. Stigma 3-lobed === 2

1. Stem, leaves and flower stalk glabrous. Stigma 2-lobed or almost globular === 3

2. Sepals abruptly long acuminate (caudate apex often longer than body, spreading or curved at maturity), hirsute-villous at base, 15-25 mm long. Leaves deeply 3-lobed or (rarely) entire. Corolla 30-45 mm long === 2. Ipomoea hederacea

2. Sepals acute-acuminate but never caudate, glabrous at base, 10-15 mm long. Leaves entire. Corolla 45-70 mm long === 5. I. purpurea

3. Leaves pedately compound === 8. I. wrightii

3. Leaves entire or lobed, never compound === 4  

4. Corolla salverform (tube long and narrow, abruptly widened at apex), crimson. Style slightly exserted. Leaves typically dentate-sinuate basally === 1. I. coccinea

4. Corolla funnelform to campanulate (tube conspicuously expanding from middle to apex), blue, white or pinkish-purple. Style inserted. Leaves variable but rarely dentate-sinuate basally === 5

5. Corolla large, 40-60 mm long, limb blue, tube white, yellow at base. Sepals with white margins, ca. 6 mm long === 6. I. tricolor

5. Corolla small, 10-25 mm long, limb white or pinkish-purple. Sepals entirely green, 5-14 mm long === 6

6. Corolla white. Capsule 10-15 mm wide === 3. I. lacunosa

6. Corolla pinkish-purple. Capsule 5-8 mm wide === 7

7. Capsule 5-6 mm across. Sepals oblong-caudate, 5-6 mm long === 7. I. triloba

7. Capsule 7-8 mm across. Sepals lanceolate-acuminate, 10-13 mm long === 4. I. x leucantha

Additional alien: Ipomoea hederifolia L. (syn.: Ipomoea angulata Lam., I. coccinea var. hederifolia (L.) A. Gray, Quamoclit hederifolia (L.) G. Don) (Am., wool alien; see Lambinon 1995).


Literature

Alarcón-Bravo L., Torres-Reaño G., Austin D.F., Rojas-Idrogo C. & Delgado-Paredes G.E. (2016) Sinopsis de Ipomoea L. y Merremia Dennst. Ex Endl. (Convolvulaceae) en el norte del Perú (Lambayeque y territorios adyacentes). Acta Botanica Malacitana 41: 101-120. [available online at :
http://www.biolveg.uma.es/abm/Volumenes/vol41/41_Alarcon_Bravo.pdf]

Austin D.F. (2006) Noteworthy distributions and additions in southwestern Convolvulaceae. Canotia 2(3): 79-106. [available online at:
http://www.canotia.org/volumes/CANOTIA_2006_Vol2_3_Austin.pdf]

Austin D.F. & Huáman Z. (1996) A synopsis of Ipomoea (Convolvulaceae) in the Americas. Taxon 45: 3-38.

Eserman L.A., Tiley G.P., Jarret R.L., Leebens-Mack J.H. & Miller R.E. (2014) Phylogenetics and diversification of morning glories (tribe Ipomoeeae, Convolvulaceae) based on whole plastome sequences. Am. J. Bot. 101(1): 92-103.

Grøstad T., Halvorsen R. & Elven R. (2002) Fremmede planter i Norge: praktvindlene Ipomoea L. Blyttia 60(1): 15-30.

Hyam R.D. (2000) Ipomoea. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 115-117.

Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.

Khalik K.A. (2013) Systematic implications of seed coat diversity in some representatives of the genus Ipomoea (Convolvulaceae). Turk. J. Bot. 37: 811-824. [available online at: http://journals.tubitak.gov.tr/botany/issues/bot-13-37-5/bot-37-5-3-1302-56.pdf]

Lambinon J. (1995) Notes taxonomiques, nomenclaturales et chorologiques relatives à la quatrième édition de la « Nouvelle Flore » de la Belgique et des régions voisines. 3. Données nouvelles sur des plantes adventices ou subspontanées en Belgique. Dumortiera 60: 1-36.

Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.

Wood J.R.I., Carine M.A., Harris D., Wilkin P., Williams B. &  Scotland R.W. (2015) Ipomoea (Convolvulaceae) in Bolivia. Kew Bull. 70 [available online at: http://link.springer.com/article/10.1007%2Fs12225-015-9592-7]

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith