Morning Glories of Monteverde

Key to the Species of Ipomoea (Convolvulaceae)

The genus Ipomoea is represented by about 50 species in Costa Rica, with 15 recorded in the Monteverde region. All but the cultivated I. indica grow naturally on the Pacific slope, and at least two species (I. batatas and I. batatoides) also occur on the Atlantic slope. Operculina pteripes, with flowers similar to Ipomoea, is also included in the key. Most of these species can be seen along the roads between the Inter-American Highway and Monteverde, where they are especially noticeable during the peak flowering season from November to January.

Most Morning Glories are climbers without stipules or tendrils and with alternate simple leaves. The leaves are often lobed, and the amount of lobing can be highly variable even on the same plant. Many species produce copious white latex when cut; a few have clear sap. Most of the above ground growth tends to be herbaceous and annual, so that plants reach their full growth at the end of the growing season- hence the concentration of flowering from November to January- at the end of the rainy season. A few species have semi-woody, perennial stems, and are deciduous (e.g., I. aurantiaca, I. leucotricha).

Flower parts

1a. Corolla dark blue or purple ... 2

2a. Corolla blue with a white throat, calyx lobes long and narrow, leaves pubescent ... 3

3a. Corolla light blue, calyx lobes hairy, growing wild ... I. nil

3b. Corolla dark blue, calyx lobes nearly glabrous, cultivated ... I. indica

2b. Corolla dark blue with a yellow throat, 5 cm long, 5 cm diameter, leaves glabrous, growing wild, Pacific slope at 700-900 m ... I. parasitica

2c. Corolla purple with throat purple-black except at very base, calyx lobes short and rounded, leaves glabrous, common on Pacific slope at 800-1300 m ... I. lindenii

2d. Corolla purple-blue with paler pink or magenta throat, stems and leaves pubescent, calyx lobes pointed and revurved, uncommon at 1100-1200 m ... I. leucotricha

1b. Corolla white ... 4

4a. Corolla tube long and narrow, about 12 cm ... I. alba

4b. Corolla tube short, less than 3 cm ... 5

5a. Corolla tube about 3 cm, open at night ... I. santillianii

5b. Corolla tube less than 1 cm, base of throat often purple, open during day ... I. batatoides

1c. Corolla lilac, pink or lavender with a darker throat ... 6

6a. Calyx with many 1 cm soft spines ... I. setosa

6b.Calyx without spines ... 7

7a. Calyx lobes long and pointed ... 8

8a. Calyx lobes and stem almost glabrous, corolla 4-5 cm in diameter, 4-5 cm long, common above 1200 m ... I. batatas

8b. Calyx lobes and stem with abundant long hairs, corolla 3 cm in diameter, 2.5 cm long, limb white or pale pink with 5 distinct lobes, common below 700 m ... I. trifida

7b. Calyx lobes short and rounded ... 9

9a. Calyx lobes with a central ridge line and a small tooth at apex, base of corolla tube white inside, peduncle ridged or winged, common at 700-1100 m ... I. umbraticola

9b. Calyx lobes without a central ridge line, base of corolla tube gray inside, peduncle not ridged or winged, uncommon on Pacific slope at 700-1100 m ... I. batatoides
1d. Corolla yellow-orange ... I. aurantiaca

1e. Corolla scarlet, 2 cm across when open, Pacific slope below 500 m ... I. hederifolia

1f. Corolla salmon, Pacific lowlands up to 500 m ... Operculina pteripes

| Ipomoea image gallery | Picture key | Species list | Plant page | Monteverde page |

Images and text copyright © 2001 by William A. Haber,
Created: 11 January 2001; updated: 6 November 2001.