Native Hawaiian Garden (7722) - Pā‘ū-o-Hi‘iaka

Pā‘ū-o-Hi‘iaka (Jacquemontia sandwicensis) – Native, Hawaiian, or both?

For the past 20-plus years, I have lived and worked on the Leeward Coast of O‘ahu (Nānākuli to Makua), a community in which the majority of residents self-identify as native Hawaiian. During that time, more often than I would like, I have had to explain to my neighbors why I consider plants like kalo (taro), ‘uala (sweet potato) and wauke (paper mulberry) to be Hawaiian but not native. Let me elaborate. Botanists in Hawai‘i divide the plants found here into four major groups: endemic (plants found only in Hawai‘i), indigenous (plants found in Hawai‘i and elsewhere, arriving in Hawai‘i without human assistance), Polynesian-introduced (plants found in Hawai‘i and elsewhere, arriving in Hawai‘i with Polynesian voyagers before 1778), and recently-introduced or alien (plants found in Hawai‘i and elsewhere, arriving in Hawai‘i with humans after 1778). Further, we classify the first two groups, endemic and indigenous, as native because humans did not bring (i.e., introduce) them, intentionally or not, to Hawai‘i. The definition of Hawaiian for botanists like myself is not equivalent to native. Rather, Hawaiian plants include all plants native to Hawai‘i plus the Polynesian-introduced plants. So, a plant such as kalo, a Polynesian-introduction, is Hawaiian but not native, while a plant such as pā‘ū-o-Hi‘iaka, a species endemic to Hawai‘i, is both native and Hawaiian. (As a side note: Do not let a plant’s name confuse you regarding its classification. There are lots of plants in Hawai‘i that have Hawaiian names such as kiawe (recently-introduced) that are neither Hawaiian nor native. Similarly, there are many plants in Hawai‘i with no known Hawaiian name such as Bonamia menziesii that are native and, therefore, Hawaiian.)

Habitat & Appearance: Pā‘ū-o-Hi‘iaka is a perennial herbaceous non-climbing vine endemic to the main Hawaiian Islands. (Some classify pā‘ū-o-Hi‘iaka as an endemic subspecies, sandwicensis, of a more widespread indigenous species, Jacquemontia ovalifolia.) It is common in coastal areas and grows on many substrates including rock, sand, and clay. Like other members of the Morning glory family (Convolvulaceae), pā‘ū-o-Hi‘iaka has partially-folded leaves along the mid-vein and tubular flowers. The elliptical leaves can be densely tomentose (fuzzy) to glabrate (hairless). Flowers are pale purple, pale blue or white.

Ripe fruits (capsules) and seeds. Seedlings of varying ages. Adult pā‘ū-o-Hi‘iaka with flowers at Kalaeloa, O‘ahu.

Pā‘ū-o-Hi‘iaka in Hawaiian Culture: Early one morning, Pele carried her baby sister Hi‘iaka to the ocean, laid her down on the beach, and left her to go surfing. As Pele surfed, the sun began to rise high in the sky and burn the sensitive skin of Hi‘iaka. Nearby, a native vine saw what was happening to Hi‘iaka and quickly grew to cover the baby and protect her. Hours later, Pele returned from surfing but could not find her sister. Finally, she discovered Hi‘iaka hidden under the many leaves of the vine. Only then did she realize how irresponsible she had been and spoke to the vine; Thank you, protector of my beloved sister. From this day forward, you will be known by all the Hawaiian people as Pā‘ū-o-Hi‘iaka, the skirt of Hi‘iaka. (Neal 1965).

(The following is from nativeplants.hawaii.edu thanks largely to the research of David Eickhoff.) Ancient Hawaiians used pā‘ū-o-Hi‘iaka medicinally to treat babies for a variety of ailments including thrush (ʻea), general weakness (pāʻaoʻao), and ʻeha makaʻu (frightening pains or aches). For adults, it was also used for ʻeha makaʻu, as well as a laxative for constipation (lepo pa‘a). Dried leaves and stems were made into a tea or mixed with coconut and eaten. Mixed with kalo leaves and salt, pā‘ū-o-Hi‘iaka was used to heal cuts.

Collecting Seeds: In my experience, pā‘ū-o-Hi‘iaka flower and fruit most of the year except during extreme drought. (Others have noted a peak in flowering between December and July.) Collect the wedge-shaped seeds from dry tan capsules. Discard any seeds which float in water; these are inviable. I have never kept pā‘ū-o-Hi‘iaka seeds for longer than a year before sowing (without any noticeable loss in viability). I suspect they would remain viable for years if stored in a refrigerator. Anne Frances found Jacquemontia reclinata, a related endangered species in Florida, to have orthodox seeds and store well under a variety of conditions.

Growing from Seed: Nearly no one propagates pā‘ū-o-Hi‘iaka from seed because it is so much easier to grow from cuttings. In contrast, along a Hawaiian shoreline after a heavy rain(s), tiny seedlings abound, and this is how a natural pā‘ū-o-Hi‘iaka population expands. So, in addition to the increased genetic diversity from seeds versus cuttings, there may be merit in mimicking natural processes if for no other reason than learning more about nature.

Sow the seeds in any clean media, however, I prefer to use washed coral sand because it makes it easy to separate the seedlings from a community pot (see photo to the right). I have tried numerous seed pretreatments (e.g., presoaking, hot water, gibberellic acid) to speed or increase germination; none had any significant effect. Pretreated or not, the first spouts appear in about two weeks and seeds continue to germinate for another three months. Separate and repot the seedlings after they have 2-3 true leaves. This is also a good time to lightly fertilize the repotted seedlings to speed their growth; I prefer controlled-release pellets but weekly waterings with a dilute liquid fertilizer also work well. With the fertilizer, the seedlings grow quickly, and in 1-2 months you should have a 6-12 inch long vine ready for restoration outplanting or a place in your garden.

In the nursery, seedlings are often attacked by sap-sucking pests such as mealybugs and whiteflies. Refer to Enemies in the Garden for ways to combat these pests. Additionally, pā‘ū-o-Hi‘iaka seedlings are a tasty nighttime salad for any snail or slug residing in your nursery; be on watch for disappearing seedlings or leaves. Deter these herbivores by installing copper barriers around the seedlings, using snail and slug traps, or bait poisons.

Growing from Cuttings: Pā‘ū-o-Hi‘iaka stem-tip cuttings root easily using Methods One, Two or Three, with or without a rooting hormone treatment. Typically, roots will begin developing within a few days to a week, however, it usually takes 3-6 weeks until the cutting becomes a self-sufficient new plant. In my experience, the two most common rooting failures are: (1) an overlooked insect pest such as a whitefly or mealybug rapidly reproduces and kills the cutting, and (2) a fungus quickly attacks, blackens, and kills the cutting. Obviously, to avoid the first case, you should frequently inspect the cutting for any pests and immediately remove them by hand or by gently re-washing the cutting’s leaves and stems. (Using an insecticide is often too harsh and will kill the cutting.) To avoid the second case, it helps to reduce the humidity surrounding the cutting either by reducing the misting frequency (Method Two) or providing more air circulation with additional holes in the container (Methods One & Three).

Growth in the Garden: Pā‘ū-o-Hi‘iaka grows best with lots of sunlight and very little water. For coastal restorations, it is one of my go-to plants, and there are several sites on O‘ahu where our plantings have survived, persisted, and reproduced for many years. In contrast, I have never had such success with pā‘ū-o-Hi‘iaka in an inland garden setting. Always, after 2-3 years in the garden, some pest would attack my plants and overwhelm my ability to keep them alive. However, I do not want to discourage you. Other native plant enthusiasts I have talked with have kept their pā‘ū-o-Hi‘iaka alive in their gardens for a much longer time. I suspect location as well as other factors such as watering, soil type, and companion plants are responsible for such varied survivorship. My best success with pā‘ū-o-Hi‘iaka is as a container plant. In a container, it was easy for me to monitor and treat my plant if it was attacked by pests or simply move it to a safer location. A pā‘ū-o-Hi‘iaka in a hanging basket on your lanai is a particularly beautiful display. Lastly, some anecdotal evidence suggests that regularly misting your plant with seawater may be a prophylactic for pests as well as a natural fertilizer.

Diseases & Pests: Mature pā‘ū-o-Hi‘iaka are plagued with the same pests as seedlings: sap-sucking pests (e.g., mealybugs, whiteflies, scale insects) and herbivorous snails and slugs. Refer to Enemies in the Garden for ways to combat these insects. Often, because pā‘ū-o-Hi‘iaka grows along the ground, it is easy for ants to re-infest your plant with mealybugs, etc., at multiple points, turning pest-control into a game of whack-a-mole. If the job becomes overwhelming, I suggest moving your plants back into pots; this will make it easier for you to treat them. Deter snails and slugs by installing copper barriers around your plants, using snail and slug traps, or bait poisons.

Ā ā Ē ē Ī ī Ō ō Ū ū