Tropical Plant Database - Plant Details

Description:
Ixora hookeri, also known as Fragrant Ixora, is a shrub or small tree that grows to 5.5 m tall. Like all members of the Madder (Rubiaceae) family, Ixora has opposite leaves that have small bracts, called stipules, on the stem between the leaves. The leaves are ovate to lance-shaped and grow up to 30 cm long and 7 cm wide. Fragrant ixora flowers develop in a cluster at the tip of the branches, with white to pink flowers producing a vibrant display of color amongst the leaves. The flower petals are long and fused into a tube at the base that can be up to 12 cm long with four narrow petals lobes that spread widely at the tips. The flowers are fragrant especially in the morning. The small, red to black fruit contains two seeds.

(Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants cultivated in the Hawaiian Islands and other tropical places. Bishop Museum Press, Honolulu, Hawai’i.)

Geographic Distribution:
Fragrant Ixora is native to Madagascar where it is found in humid forests. It is widely cultivated in tropical regions worldwide and was introduced into Hawaii in 1935. The genus Ixora contains approximately 300 species with a pantropical distribution and a center of diversity in Southeast Asia and Oceania. Madagascar has 35 Ixora species all of which are endemic.

(De Block, P. J. Tosh, A. Mouly, and S. Dessein. 2007. The diversity of Madagascan Ixoras revealed, with comments on their origin and their radiation on the island. Oral presentation to the 17 AETFAT Congress, 26 February-2 March, 2007 in Yaounde, Cameroon.)
(Staples, G. W. and D. R. Herbst. 2005. A Tropical Garden Flora: Plants cultivated in the Hawaiian Islands and other tropical places. Bishop Museum Press, Honolulu, Hawai’i.)
(Stevens, P. F. (2001+). Angiosperm Phylogeny Website. Version 7, May 2006 [updated 05/28/2007]. http://www.mobot.org/MOBOT/research/APweb/.)

Flowers produce nectar to ensure insects visit them and in doing act as pollinators for the plant moving pollen between different flowers so that fertilization takes place and fruit will develop. The tubular shape of Fragrant ixora flowers prevents many insects from gaining access to the nectar that is stored at the base of the floral tube. The nectar is only accessible to insects, such as hawkmoths, whose mouthparts are long enough to reach to the base of the floral tube. As these insects reach into the floral tube to obtain the nectar they touch the pollen producing structures, or stamens, and transport that pollen to other flowers they visit to obtain more nectar. Fragrant ixora seldom produces fruits outside of Madagascar because the specialist insect pollinator is not present. Without the specialist insect pollinators to move pollen between flowers, fruit, which only develop following fertilization (of the ovule by the pollen), are not produced.

The genus name Ixora is named after a deity called Iswara, who is recognized in the southwestern Indian region of Malabar, to whom the flowers are offered.

We currently have 3 herbarium specimens for Ixora hookeri in our collection. Click on any specimen below to view the herbarium sheet data.

• 027950 - collected by David H. Lorence in 1997
• 035289 - collected by David H. Lorence in 2001
• 082257 - collected by Tim Flynn in 2020