Portulaca lutea,
Portulaca molokiniensis,
Portulaca sclerocarpa &
Portulaca villosa
Portulacaceae or Purslane family
Synonyms: P. villosa ⇨ Portulaca caumii, Portulaca hawaiiensis, Portulaca pilosa subsp. villosa
Embedded Files
ʻIhi
P. sclerocarpa ⇨ ‘Ihi mākole, Po‘e
P. lutea ⇨ Yellow purslane
P. villosa ⇨ Hairy purslane
Natural Range & Environment
Portulaca lutea is found in the Pacific from New Caledonia to Pitcairn Island and north to Polynesia and Micronesia. In Hawai‘i, it is indigenous to all the Northwestern Islands except for Pearl and Hermes Atoll, as well as all the main Hawaiian Islands [Flora of the Hawaiian Islands], where it grows in coastal and strand habitats from sea level to 40 m (131 ft) on lava, raised coralline reefs, sand dunes, and in soil pockets or cracks [Wagner et al. 1990].
Portulaca molokiniensis is a rare species endemic to Molokini Island (Maui), and Kamōhio Bay and Puʻukoaʻe Islet (Kahoʻolawe) from 10 to 115 m (33 to 377 ft). It grows in volcanic tuff, detritus at the base of sea cliffs, and on steep rocky slopes [Wagner et al. 1990].
Portulaca sclerocarpa is federally listed as an endangered species. Historically, it grew on Po‘opo‘o, an islet off the south coast of Lāna‘i, and on Hawai‘i Island in the Kohala mountains, on the northern slope of Hualālai, the northwestern slope of Mauna Loa, and near Kīlauea Crater. As of 2020, it is no longer found on Po‘opo‘o, but still grows in the Pōhakuloa Training Area, Hawai‘i Volcanoes National Park, the Kaʻū Desert, and Pu‘uanahulu on Hawai‘i Island [USFWS;ECOS].
At the time of its listing (1994), there were about ten known plants on Po‘opo‘o and about 100 known plants on Hawai‘i Island. Later USFWS reports (1996, 2003) increased the Hawai‘i number to about 1,000. However, in 2012, USFWS reported that there were no plants found on Po‘opo‘o and only about 200 on Hawai‘i Island. In 2020, the Hawai‘i Island population was reported to be about 450 wild plants at ten locations; however, some botanists think the number is more likely in the thousands and that more surveys are needed. Fortunately, more than 2,000 plants have been reintroduced with a survival rate greater than 60% after two years. Additionally, there has been extensive seed collection and storage, captive propagation, and some fencing to protect the more vulnerable populations [USFWS;ECOS].
On Hawai‘i Island, Portulaca sclerocarpa grows on weathered Mauna Kea soils, cinder cones, and young lava in montane dry shrubland. It is typically seen on bare cinder, near steam vents, and in open ‘ōhi‘a lehua (Metrosideros polymorpha) forests from 351 to 2,274 m (1,152 to 7,461 ft) [USFWS;ECOS].
Portulaca villosa is an uncommon endemic Hawaiian species found on Nīhoa (Moku Manu) as well as Kaʻula, a small islet southwest of Niʻihau, but strangely, it is not known to naturally occur on nearby Niʻihau or Kauaʻi. Additionally, it grows naturally on all the other main Hawaiian Islands. This ‘ihi is found on dry rocky, clay, lava, or coralline reef sites from sea level to over 300(–490) m (984[–1,608] ft) [Wagner et al. 1990].
Portulaca lutea leaves and flowers (yellow), in a container, and open fruit with tiny seeds (All Portulaca lutea photographs courtesy of Forest & Kim Starr CC BY 3.0). Flowering (yellow) Portulaca molokiniensis in a container. Portulaca sclerocarpa leaves and flower (white). Species comparison: large terracotta pot ⇨ Portulaca molokiniensis, small terracotta pot ⇨ Portulaca sclerocarpa, Cement pot ⇨ Portulaca villosa. Purple flower form of Portulaca villosa (Note the white flower form in header). ʻIhi store water in their roots to endure drought conditions.
Description
All four native Portulaca are short (up to about one foot (30 cm) tall for P. molokiniensis, the tallest) and have fleshy stems and leaves. In cultivation, they all have a lifespan greater than five years. The four species can be evenly divided with two species, P. lutea and P. molokiniensis, having yellow flowers and flattened scallop-shaped leaves, while the other two species, P. sclerocarpa and P. villosa, have white or white and pink/purple flowers and slender leaves.
The easiest way to distinguish Portulaca lutea from P. molokiniensis is their differing growth form, flower position, and stem color. P. molokiniensis is a much more upright plant than P. lutea with thicker stems and dense flower clusters at the top of a long stalk. In contrast, P. lutea is typically prostrate with its flowers developing close to its leaves. Additionally, while P. molokiniensis may have a hint of red in its flower stalks, its vegetative stems are always gray. In contrast, the stems of P. lutea are often red or have reddish hints.
Look to the leaves to distinguish Portulaca sclerocarpa from P. villosa. P. sclerocarpa has pointed lance-like leaves while the leaves of P. villosa are long flattened ovals.
All the native ‘ihi have perfect (bisexual) flowers, typically with five petals. Each flower opens for a day and can be both self- and cross-pollinated. Cultivated ‘ihi go through cycles of blooming, fruit development, and rest (i.e., no flowers or fruits). Unfortunately, we have not been diligent enough to completely determine the length and frequency of the cycle for each species. However, generally, cycles seem to be less than a year long (i.e., there is more than one cycle annually) for cultivated plants, with peaking flowering during the summer months. The pollinated flowers develop into round capsules. When ripe, each capsule contains dozens of tiny round brown to black seeds.
Growth Requirements
General
Unless you are willing to maintain a constant vigil for snails and slugs, rats and mice, and chewing insects like cockroaches, we strongly advise you to never plant any of these four ‘ihi in the ground, but, rather, keep them in a container, preferably elevated two or more feet above the ground. And, while all four species will grow (and possibly flower) more when placed in a site with full sunlight for all or most of the day, they can also be grown inside near a sunny window or under bright lights (e.g., daylight LEDs); it can also be safer to keep them inside.
ʻIhi does best when minimally watered and kept in a fast-draining medium/media such as black cinders or a "cactus mix." Always let the surface of the media dry before watering again. Cement, terracotta, or unglazed ceramic pots are better (but not required) than plastic pots because they "breathe" and prevent permanent wet spots within the pot that can lead to root or stem rot. Additionally, these heavier pots help prevent your ‘ihi from toppling over during a windstorm as they grow larger.
All the ʻihi I (Koebele) have ever grown were propagated by rooting cuttings. Therefore, I cannot comment on the growth of seedlings. Generally, these cloned plants grew at a slow to moderate pace and never (expectedly) got very large. However, because they were cuttings, all but my Portulaca molokiniensis began flowering and fruiting in less than a year.
‘Ihi can tolerate drought, heat, wind, salt spray, and becoming root-bound. Because your ‘ihi is in a container, apply a balanced controlled-release fertilizer with minor elements about every six months or spray your plant every month or so with a water-soluble organic or inorganic fertilizer diluted to ⅓ to ½ the recommended strength. Avoid pruning your ‘ihi except to remove dead leaves, ripe seed capsules, or old stalks. However, all of these will eventually drop off if left untouched.
Native Portulaca can cross-pollinate with other native and alien Portulaca [Kim & Carr 1990]; therefore, the safest way to propagate ‘ihi is either by rooting stem cuttings or division rather than sprouting seeds.
Pests and Diseases
As mentioned above, ‘ihi is a welcome midnight snack for snails and slugs, rats and mice, and chewing insects like cockroaches. If you see any chewing damage on your plant, the easiest thing to do is move it to another location several yards away. Afterwards, if you see new damage, carefully examine the plant's pot, outside and inside, to discover any pest that might be hiding. (If possible, very gently and carefully, loosen and remove the pot from your plant's rootball and attached media to see if any animals are hiding between the media and the pot.) If you still cannot find the cause of the damage, consider making your ‘ihi less palatable by spraying it with neem oil, a mint oil, or a systemic insecticide.
ʻIhi are also vulnerable to spider mites, particularly in windless sites or inside. Scale insects and mealybugs (between the leaves or on the roots) can also occasionally infest ‘ihi; find root mealybugs by carefully removing the plant's pot as described above. Refer to the Pests & Diseases page for ways to eliminate these sap-sucking pests. Stem or root rot can become a problem, but only if you disregard our advice above and keep the media in your plant's pot constantly wet.
Uses
Ancient Hawaiian
Krauss [1993] states that the entire ‘ihi plant, a native (but unspecified) purslane species, was mixed with the bark of ‘ōhi‘a ‘ai (Syzygium malaccense) and whole ‘āwikiwiki (Canavalia spp.) plants, pounded thoroughly, added to water, mixed, strained, and then heated. When cool, the mixture was applied to itchy skin or other skin disorders.
Both Ka‘aiakamanu [2003] and Neal [1965] describe medicinal uses of ‘ihi mākole; however, both seem to be referring to an alien wood-sorrel species (most likely Oxalis corniculata).
Modern
Special Features and Information
General
The Purslane family (Portulacaceae) is currently comprised of about 115 species in a single genus, Portulaca, which has a worldwide distribution. (Formerly, about 20 genera with about 500 species were placed in this family. However, today, it is restricted to the genus Portulaca with the other genera being placed elsewhere.) Many Portulacaceae species have succulent leaves and colorful flowers (like our native species) and are popular ornamentals [WikipediA;Portulacaceae].
The naturalized alien purslane, Portulaca oleraca, sometimes called ‘ihi in Hawai‘i (but more often referred to as pigweed) is a commonly cooked and eaten vegetable in soups, stews, and salads, and used worldwide in folk medicine [Hawaii Horticulture].
Hawaiian Name
ʻIhi is the Hawaiian name used for all four native Portulaca species. However, Portulaca sclerocarpa has two additional names, ‘ihi mākole and po‘e. Hawaiian Dictionaries notes poʻe as meaning "people, persons, personnel, population, assemblage, group of, company of."
Etymology
Portulaca is from the Latin word porto, meaning "I carry," and lac, meaning "milk," combined to mean "milk-carrier." The species name, lutea, is Latin for "yellow," referring to the bright yellow flowers of this species [Gledhill 2008].
The species name, molokiniensis, refers to Molokini Island off Maui's southern coast, one of the few places this rare species can be found growing naturally. The suffix -ensis was added to Molokini to Latinize the name [Gledhill 2008].
The species name, sclerocarpa, comes from the Greek words for "hard" and "fruit" [Gledhill 2008].
The species name, villosa, is Latin for "with long rough hairs" or "shaggy," referring to the hairs emerging from the leaf axils of this species [Gledhill 2008].
BPK
Page updated
Google Sites
Report abuse