Kaunaʻoa has tiny, star-like yellowish-white, perfect (bisexual) flowers (photograph courtesy of Eric Knight CC BY 4.0). This parasitic plant uses its tiny claw-like haustoria pictured here to penetrate and absorb nutrients from other plants (photograph courtesy of G.K. Linney via G.D. Carr ©). While its most commonly seen host is pōhuehue (Ipomoea pes-caprae subsp. brasiliensis) (photograph courtesy of Forest & Kim Starr CC BY 3.0), kaunaʻoa will parasitize many other species of native and non-native plants in Hawai‘i (photograph of kaunaʻoa on unidentified roadside plant and cultivated native hibiscus courtesy of Scot Nelson, Public Domain; photograph of kaunaʻoa on hinahina kū kahakai (Heliotropium anomalum) courtesy of Forest & Kim Starr CC BY 3.0 US).

Growth Requirements

General

    I (Koebele) have never purposefully grown kaunaʻoa. However, it has always eventually appeared within my coastal restoration sites if it wasn't already present. Bornhorst [2005] states it is easy to grow either by taking cuttings and wrapping them around a host plant —kaunaʻoa isn't picky and almost any plant will do —or smearing the seeds on the stems of a host plant, or planting the seeds in a pot already containing a host plant(s).

    Kaunaʻoa will parasitize many different species of both native and non-native plants in Hawai‘i. Because it is found in coastal areas, its hosts are mostly coastal species, with probably pōhuehue (Ipomoea pes-caprae subsp. brasiliensis) being its most common host. (See Wagner et al. [1990] for a partial list of recorded hosts.) However, other non-coastal plants such as hibiscus (see photograph above) can also be used as a host plant. When selecting a host plant, it's very important to remember that kaunaʻoa is a parasite quite capable of killing its host. Therefore, if cultivated, it should be pruned or harvested often, preferably from a non-valuable host plant. Bornhorst [2005] recounts how her friend, Craig Doyle, a teacher at the University of Hawai‘i Lab School, would grow kaunaʻoa on the weeds near his parking space. I always prefer to let kaunaʻoa grow on ʻakiʻaki (Sporobolus virginicus), where it seems to cause the least damage, while removing it from any of my other coastal plantings. As a side note to lei-makers, kaunaʻoa growing on ʻakiʻaki or other grass species is easy to harvest with little physical damage to the grass. 

    If you intend to grow kaunaʻoa simply as a feature, you should isolate it on one or two host plants in your landscape or confine it to a pot with its host plant(s). However, if you intend to grow it for lei, you'll need to devote a greater space since kaunaʻoa doesn't grow superfast. Perhaps easiest is dedicating a portion of your lawn or two or more large vigorous shrubs to serve as hosts. Unfortunately, as our Islands' population continues to grow, collecting wild kaunaʻoa has become less and less sustainable, particularly on O‘ahu. 

    Wild kaunaʻoa is seen most often in coastal areas. Therefore, use this as a guide for its best growing conditions. In other words, provide your kaunaʻoa with lots of direct sunlight. In regard to water and soil, cater these to the preferences of the host plant(s) since kaunaʻoa lacks roots (except when very young) and relies on its host for water and nutrients. Regularly fertilizing the host plant is likely — we need an experiment here — to improve its vigor, extend its life, and consequently, improve the growth of the attached kaunaʻoa. Kaunaʻoa can tolerate extreme heat, strong winds, salt spray, and drought (to the extent that the host plant remains alive). As mentioned above, regular pruning is important to both confine kaunaʻoa to a selected area or selected plants and to prevent the host plant(s) from dying. 

Pests and Diseases

    I (Koebele) have never seen any pests or diseases on kaunaʻoa. However, it supposedly can transmit viruses to its host plant(s) [CTAHR; WikipediA;Cuscuta].

Special Features and Information

General

    There are about 1,600 species within about 60 genera in the Morning glory family (Convolvulaceae), distributed worldwide in both tropical and temperate areas. Most members are twining or erect herbs, with some woody vines, trees, and shrubs [Britannica]. Locally popular food plants in Convolvulaceae include ʻuala or sweet potato (Ipomoea batatas) and ung-choi or swamp cabbage (I. aquatica).

    In addition to Cuscuta sandwichiana, native Hawaiian members of Convolvulaceae include: the endemic and endangered Bonamia menziesii; the indigenous makihi (Cressa truxillensis); the indigenous hunakai (Ipomoea imperati), koali ʻawa (I. indica), pōhuehue (I. pes-caprae subsp. brasiliensis), and White-flowered beach morning glory (I. littoralis); the endemic Hawaiian moon flower (I. tuboides); and the endemic pāʻūohiʻiaka (Jacquemontia sandwicensis) [Flora of the Hawaiian Islands].

    The genus Cuscuta contains over 200 species of yellow to red (or rarely green) parasitic plants. It was formerly the only genus in the now invalid plant family, Cuscutaceae. However, recent DNA research now places it in the Morning glory family, Convolvulaceae, the same family as its most commonly seen natural host, pōhuehue (Ipomoea pes-caprae subsp. brasiliensis). Cuscuta species are found throughout the temperate to tropical regions of the world, with the greatest species diversity in subtropical and tropical regions [WikipediA;Cuscuta].

    Cuscuta sandwichiana is the only native member of the genus Cuscuta in Hawai‘i. However, as of 2026, there are also two non-native species, C. campestris and C. pentagona, which have naturalized on some of Hawai‘i's main islands [Flora of the Hawaiian Islands].

    Neal [1965] notes that kaunaʻoa is often called "the motherless plant" in old Hawaiian literature and provides the example: "Kaunaʻoa vine, vine of Mana; how I love that orphan vine."

Hawaiian Name

    Kaunaʻoa shares its name with: (1) a Vermetidae mollusk (worm snail), also called kaunoʻa (a second shared name), that attaches to rocks; Hawaiians believe a cut from stepping on this animal is deadly poisonous; and (2) a golden, tough, calcified, and inedible seaweed (Galaxaura rugosa) that resembles kaunaʻoa in appearance [Pukui & Elbert 1986].  

    Kahakai, meaning "beach" or "seashore" [Pukui & Elbert 1986], likely refers to the natural coastal habitat of this species.

    Pōlolo, another Hawaiian name for kaunaʻoa pehu (Cassytha filiformis), is sometimes improperly used for Cuscuta sandwichiana [Pukui & Elbert 1986].

Etymology

    Cuscuta is the name used by Rufinus, a 13th-century botanist, for dodder [Gledhill 2008], originating from a series of Arabic words, possibly meaning "to pile up" and likely referring to the network of vines wrapping around a host plant [Wiktionary]. Gledhill [2008] is likely referring to The Herbal of Rufinus, written by a 13th-century monk and edited and published by Lynn Thorndike and Francis S. Benjamin, Jr. in 1946 [Encyclopedia;Rufinus].

    The species name, sandwichiana, is a reference to the "Sandwich Islands," the name given to the Hawaiian Islands by James Cook on one of his voyages in the 1770s. He named the islands after John Montagu (the fourth Earl of Sandwich) for supporting his voyages [Gledhill 2008].