Jacquemontia ovalifolia is an herbaceous vine that grows in dense clumps within coastal strand vegetation. Pā‘ūohi‘iaka can establish in exposed sandy and rocky substrates and, once established, produces long horizontal stems that become anchored in the substrate through the production of roots at the nodes along the stem (point at which leaves are attached). The stems of Pā‘ūohi‘iaka grow up to 3 m long, meaning it is able to cover large areas providing essential vegetative cover and preventing sand and soil erosion. The stems of Jacquemontia ovalifolia are covered in dense hairs that are two-branched. This provides a feature for botanists to distinguish this native species from an introduced species, Jacquemontia pentantha, which has three-branched hairs.
The plants present in Hawai‘i are slightly different than Jacquemontia ovalifolia plants found in other parts of the world and are therefore recognized as a distinct subspecies; Jacquemontia ovalifolia subspecies sandwicensis. In the Hawaiian subspecies the above ground plant surfaces tend to be densely hairy; however, these hairs may be lost over time so that the leaves and stems appear glabrous or smooth. The thick and somewhat fleshy leaves are predominantly longer and wider in Hawaiian plants (4-6 cm long and 1.5-3.5 cm wide) than in plants found elsewhere (0.7-6 cm long and 0.6-3.5 cm wide). All Jacquemontia ovalifolia subspecies have leaves that are widest in the middle that gradually narrow to the base and are rounded at the leaf tip.
The pale blue or white flowers of Jacquemontia ovalifolia are borne in clusters in the leaf axils (in the angle between the leaf and the stem). The flowers are characteristic of the family Convolvulaceae: the five petals are partially or fully fused to form a tube which is narrow at the base and widely spreading at the tip and fold lines, or plaits, can often be seen that reflect the way the flower was folded in the bud. The petals of Jacquemontia ovalifolia subspecies sandwicensis are 10-15 mm long, which is generally longer than those of other subspecies that range from 7-15 mm long. While Jacquemontia ovalifolia flowers can be seen throughout the year the flowering peak is from December to July. The fruit of Pā‘ūohi‘iaka is a dry capsule (4-6 mm wide) that is partially enclosed in the persistent calyx. The capsule is divided into two sections (carpels) and contains 1-4 triangular seeds (2-3 mm long) that may be winged on the margins. The small seeds have distinct areoles, or demarcated sections, as a result of seed coat texture.
(Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawai‘i. Revised Edition. Volume 1. Bishop Museum Special Publication 97. University of Hawai‘i Press, Bishop Museum Press, Honolulu, Hawai‘i.)
Jacquemontia ovalifolia subspecies sandwicensis grows in the strand vegetation that is found in coastal habitats. This subspecies is endemic to Hawai‘i, meaning this is the only place in the world in which it is found. It grows on all the main Hawaiian Islands from sea level to 550 m elevation and is most abundant on the drier, leeward sides of these islands. Jacquemontia ovalifolia has the widest distribution of any species in the genus Jacquemontia and is represented in different regions by distinct subspecies. It is found in Africa (Jacquemontia ovalifolia subspecies ovalifolia), Mexico and the West Indies (Jacquemontia ovalifolia subspecies obcordata), and Hawai‘i (Jacquemontia ovalifolia subspecies sandwicensis). The species is thought to have originated in America and the method of dispersal is currently unknown. The seeds of the Hawaiian subspecies are not buoyant; therefore, water dispersal is considered unlikely. Bird-mediated dispersal is possible as the seeds are small enough to be carried in mud on bird’s feet or to be carried internally by birds and as a result of the hard seed coat pass undamaged through the bird’s digestive system.
(Robertson, K. R. 1974. Jacquemontia ovalifolia (Convolvulaceae) in Africa, North America, and the Hawaiian Islands. Annals of the Missouri Botanical Gardens 61(2): 502-513.)
The Hawaiian name Pā‘ūohi‘iaka is literally translated as Pā‘ū meaning “the wrap or skirt” of Hi’iaka. Stories tell that Pele, the goddess of volcanoes, went fishing and left her younger sister, Hi‘iaka, asleep on the beach. On her return Pele found the plant now known as Pā‘ūohi‘iaka wrapped around Hi‘iaka protecting her from the direct sun.
The genus Jacquemontia is named after a French botanical explorer, Victor Jacquemont (1801-1832) who published an early description of the Indian flora in his work titled “Voyage dans l'Inde, pendant les années 1828 a 1832” (Paris: Didot Freres, 1841-1844), following a surveying expedition to India from 1828-1832.
The name of the family Convolvulaceae in which Jacquemontia belongs comes from the term “Convolvul” meaning to twist or twine around.
(DNLR, Division of Forestry and Wildlife. Plants and Animals of Ka‘ena Point. September 7, 2006. http://www.hawaii.gov/dlnr/dofaw/nars/kaena/bios.html)
(Victor Jacquemont Papers, American Philosophical Society. 9/6/2006. http://www.amphilsoc.org/library/mole/j/jacquemont.htm.)
We currently have 17 herbarium specimens for Jacquemontia sandwicensis in our collection. Click on any specimen below to view the herbarium sheet data.