Achyranthes divaricata
| Achyranthes divaricata | |
|---|---|
| Achyranthes divaricata growing in Limahuli Garden and Preserve | |
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Amaranthaceae |
| Genus: | Achyranthes |
| Species: | A. divaricata
|
| Binomial name | |
| Achyranthes divaricata (Lorence) Di Vincenzo, Berends., Wondafr. & Borsch
| |
| Synonyms[2] | |
|
Nototrichium divaricatum Lorence | |
Achyranthes divaricata (synonym Nototrichium divaricatum), also known as Na Pali rockwort or kuluʻī (Hawaiian), is a critically endangered perennial shrub in the pigweed family, Amaranthaceae, that is endemic to the island of Kauaʻi in Hawaii.[3][4] It can only be found in three valleys on the northwestern end of the island, where it grows on north-facing cliffs and ridges.
Achyranthes divaricata are densely branching shrubs that can grow up to 50 cm tall, with most parts covered with silvery-white hairs.[3] Leaves are oppositely arranged, with leaf blades 3–7.5 cm long and 1–4.6 cm wide. Inflorescences bear several spikes, and are terminal and usually solitary, rarely 2 or 3 together, and compoundly branched. Each spike bears 8–30 small flowers.[5] There are possibly fewer than 3,000 A. divaricata plants in existence.
This species was first described as Nototrichium divaricatum by David H. Lorence in 1996. In 2024 Vanessa Di Vincenzo et al. placed the species in genus Achyranthes as A. divaricata.[2]
Description
This species is characterized by its bushy growth, typically reaching heights of between 0.3 and 2 meters.[3] Achyranthes divaricata features densely hairy branches and twigs, giving them a silvery-white appearance. The leaves are arranged oppositely, and have petioles that can vary in size and shape. Each leaf measures approximately 2-7.5 cm x 0.6-4.6 cm.[6] The plant produces unique flower clusters with multiple branches, and can contain anywhere from 4 to 66 flowers.[6]
Distribution and habitat
Achyranthes divaricata is endemic to cliffs and ridges on the northwestern end of Kaua'i, particularly in the Hanalei District and Na Pali coast.[3] It thrives at elevations of 600 to 1100 meters in areas where remnants of lowland and montane mesic forests are still present.[6][7] The primary challenges facing Achyranthes divaricata include damage and habitat loss due to the activities of feral goats, which threaten many endemic species throughout Hawai'i. Additional risks include landslides, rock falls, and non-native plants.[6]
References
- ^ Clark, M., Walsh, S., Nyberg, B. & Wood, K. 2022. Nototrichium divaricatum. The IUCN Red List of Threatened Species 2022: e.T80228656A83457106. https://dx.doi.org/10.2305/IUCN.UK.2022-1.RLTS.T80228656A83457106.en. Accessed 17 March 2025.
- ^ a b "Achyranthes divaricata (Lorence) Di Vincenzo, Berends., Wondafr. & Borsch". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 9 March 2026.
- ^ a b c d "Native Plants Hawaii - Viewing Plant : Nototrichium divaricatum". nativeplants.hawaii.edu. Retrieved 2024-10-28.
- ^ NatureServe. "Nototrichium divaricatum". NatureServe Explorer. Arlington, Virginia. Retrieved 2024-12-09.
- ^ "Find Rare Plants in Your Area". Center for Plant Conservation. Retrieved 2024-11-27.
- ^ a b c d Lorence, David H. (1996). "A New Species of Nototrichium (Amaranthaceae) from Kaua'i, Hawaiian Islands". Novon. 6 (1): 64–67. doi:10.2307/3392213. ISSN 1055-3177. JSTOR 3392213.
- ^ "Na Pali Rockwort / Center For Plant Conservation". Retrieved 2024-10-28.