Native Plants of Hawai‘i

Carex meyenii

Cyperaceae or Sedge family

Synonyms: Carex brunnea subsp. meyenii, Carex brunnea var. meyenii, Carex remyi

No known ancient Hawaiian name

(see Hawaiian Name below)

Meyen's carex, Meyen's sedge

Natural Range & Environment

Carex meyenii is indigenous to the Caroline and Hawaiian Islands. In Hawai‘i, it is found on all the main Hawaiian Islands except Kaho‘olawe, where records show it formerly existed. It is locally common in dry to mesic forests, particularly on slopes and cliffs from 180 to 1,890 m (591 to 6,201 ft) [Wagner et al. 1990].

Compare these nearly-ripe fruits to the "blooming" flowers in the header photograph (Fruits photograph courtesy of Susan Fawcett CC BY-NC 4.0; flowers photograph courtesy of embrines CC BY-NC 4.0.). A closeup view of Meyen's carex's thin leaves; note the barely visible irregular margins (Photograph courtesy of Susan Fawcett CC BY-NC 4.0.). Today (2025), unfortunately, online photographs of cultivated Meyen's carex are almost nonexistent; my (Koebele) bad for not taking photos of my plants when I was growing this species. Therefore, for the time being, here's a photograph of a particularly attractive wild Meyen's carex on O‘ahu (courtesy of Kevin Faccenda CC BY 4.0).

Description

Carex meyenii is a small (normally less than a foot [30 cm] tall) clumping sedge with short rhizomes and a lifespan greater than five years. It has glossy long (up to two feet [61 cm]) and very thin (typically less than a third of an inch [8 mm]) partially-folded grass-like leaves that are normally dark green. While this sedge's irregular leaf margins are not serrated (see photograph above), they are (like nearly all sedges) still sharp and, therefore, one should be mindful when handling the plant.

When mature, Carex meyenii begins producing spike-like panicles (a type of branched inflorescence). The tiny petal-less male and female flowers are segregated, with male flowers at the tip of the inflorescence and female flowers below (see header photograph). As the male flowers die and turn brown, the pollinated female flowers develop into small elliptical green single-seeded fruits (i.e., achenes) that darken when fully ripe. In our experience, cultivated plants bloom and produce fruits sporadically year-round.

Growth Requirements

General

I (Koebele) am not sure why Carex meyenii is not as popular as its sister species, C. wahuensis. Maybe because it is smaller? Doesn't grow as fast? Or, isn't as aggressive as C. wahuensis when competing with weeds? Still, I hope this beautiful little sedge with its long skinny leaves finds a place in more and more commercial and residential landscapes in the near future, either as an accent (in the ground or on a rock wall) or en masse as a groundcover (space the plants 1 to 2 feet [30 to 61 cm] apart). Meyen's carex also does just fine as a container plant — hanging basket anyone? Cultivated (non-Hawaiian) Carex species have been used for years outside (and inside) Hawai‘i for landscaping; check these out online for other creative landscape ideas.

Meyen's carex does best in a site that is shaded for all or most of the day. In the wild, it is seen in both dry and mesic forests, and, therefore, it's not surprising that in cultivation it survives in both surface dry and moist soil or media, provided the soil or media drains water well. I prefer to keep the soil/media surrounding my Meyen's carex consistently moist but not wet in order to keep it unstressed, green, and constantly growing. I have grown Meyen's carex in clay soils and organic-dominant media; it's likely, given wild plants are frequently seen on cliff faces, that it would also grow well in cinder/lava-dominant soil or media.

Carex meyenii grows considerably slower than Carex wahuensis. However, it becomes reproductive (i.e., produces panicles) when it is still quite small and young (one to two years in cultivation). I did not consistently fertilized my plants; therefore, I cannot comment on whether fertilizer would speed its growth. Division of large plants is the easiest method of propagation if you intend to create a cluster or groundcover. Depending on your personal aesthetic, you may want to occasionally remove the dead lower leaves and old panicles for a tidier appearance.

Pests and Diseases

Meyen's carex is rarely attacked by pests, with scale insects on the leaves and mealybugs on the roots being the most common. Refer to the Pests & Diseases page for treatments if you encounter these pests. Avoid overwatering since this seems to actually inhibit growth and encourage basal rot.

Uses

Ancient Hawaiian

None of the ten native Carex species has a (currently) known Hawaiian name. This is somewhat surprising given how common Carex meyenii and some of the other Carex species are, and that many other native sedges have ancient Hawaiian names. A likely explanation is that the ancient name(s) were lost sometime shortly after 1778 during the period when so many Hawaiians died because of introduced diseases, taking with them their combined knowledge of Hawai‘i's native flora. Without a name, any attributable uses of Carex meyenii would also be lost.

Modern

Special Features and Information

General

The large Sedge family (Cyperaceae) has about 5,500 described species in approximately 90 genera [WikipediA;Cyperaceae]. Carex is the largest genus within Cyperaceae, with about 2,000 species worldwide growing in a diversity of habitats [Wagner et al. 1990]. Of the ten species of Carex native to Hawai‘i, five are endemic and five are indigenous [Flora of the Hawaiian Islands].

Hawaiian Name

None of the ten native Carex species has a (currently) known Hawaiian name. This is somewhat surprising given how common Carex meyenii and some of the other Carex species are, and that many other native sedges have ancient Hawaiian names. A likely explanation is that the ancient name(s) were lost sometime shortly after 1778 during the period when so many Hawaiians died because of introduced diseases, taking with them their combined knowledge of Hawai‘i's native flora. Within this website, we will use the common name, Meyen's carex, for this species.

Etymology

Carex is the classical Latin name for sedge, possibly from carere, meaning "to be absent," referring to the upper portion of its floral spike, which is composed of all staminate (male) flowers and, therefore, doesn't produce seeds [Wagner et al. 1990]. The species name, meyenii, honors Franz Julius Ferdinand Meyen (1804–1840), a Prussian physician, botanist [WikipediA;Franz Meyen], and plant illustrator [Gledhill 2008] who collected the type specimen in 1831 on O‘ahu [Tropicos].

BPK