|Listed||September 30, 1994|
|Description||A sprawling tropical shrub.|
|Habitat||Rocky substrates in lowland dry mixed shrub and grassland and in montane dry shrubland.|
|Threats||Habitat loss to agricultural conversion, competition with alien plants, feeding of introduced mammalian herbivores, and increased frequency of wildfire.|
The pamakani (Tetramolopium capillare ) is a sprawling shrub in the aster family. It has stems 20-31 in (51-79 cm) long that are covered with many glands when young. The firm, stalkless leaves are involute and are usually 0.5-1 in (13-25 mm) long and about 0.01 in (0.4 mm) wide. The flower heads are situated singly at the ends of stalks 0.4-1.4 in (1.0-3.5 cm) long. Located beneath each flower head are 45-50 bracts, arranged in a structure about 0.1 in (3-4 mm) high and 0.3-0.4 in (7-10 mm) in diameter. Each flower head has 30-50 white, male ray florets, about 0.1 in (3.5-4 mm) long and 0.02-0.3 in (0.6-8 mm) wide, and surrounding 15-25 functionally female florets, about 0.1 in (3.6 mm) long and colored greenish-yellow tinged with red. The dry, one-seeded fruits (or achenes) are 0.08-0.1 in (2-2.6 mm) long and 0.03 in (0.7-0.8 mm) wide, and are topped by a white pappus comprising a single series of bristles 0.07-0.08 in (1.9-2.1 mm) long. The pamakani differs from other species of its genus by its very firm leaves with edges rolled under, its solitary flower heads, the color of its disk florets, and its shorter pappus. It differs from Tetramolopium remyi, with which it sometimes grows, by its more sprawling habit and the shorter stalks of its smaller flower heads.
The pamakani was first collected in 1819 on Maui by Charles Gaudichaud-Beaupré. He named the sterile specimen Senecio capillaris in 1830, choosing the specific epithet to refer to its very narrow involute leaves. Based on a fertile specimen collected on Maui in the 1830s it was described and named Tetramolopium bennettii in 1935. Harold St. John, after examining and comparing type specimens 30 years later, determined that Gaudichaud-Beaupré's Senecio capillaris and Sherff's Tetramolopium bennettii were actually the same species and that Sherff had placed the taxon in the correct genus. St. John then made the new combination Tetramolopium capillare in 1965; nine years later he described the new genus Luteidiscus for species of Tetramolopium with yellow disk florets, forming the combination Luteidiscus capillaris. A treatment of the genus done in 1990 did not recognize St. John's division of the genus.
Tetramolopium capillare typically grows on rock substrates at elevations between 2,000 to 3,000 ft (610-915 m) in lowland dry mixed shrub and grassland and in montane dry shrubland. Plant species associated with the higher elevation population include Dodonaea viscosa ('a'ali'i), Metrosideros polymorpha ('ohi'a), and Styphelia tameiameiae (pukiawe). 'A'ali'i, Heteropogon contortus (pili grass) and Myoporum sandwicense (naio) are associates of the other population.
Tetramolopium capillare is known historically on West Maui from Lahainaluna to Wailuku. This species is known to be extant near Halepohaku on state land in two populations that are separated by 1.8 mi (2.9 km) and contain only 12 plants.
The habitat of Tetramolopium capillare has undergone extreme alteration because of past and present land management practices, including grazing and alien plant introductions. Introduced cattle eat native vegetation, trample roots and seedlings, cause erosion, create disturbed areas into which alien plants invade, and spread seeds of alien plants. Feral cattle, formerly found on Maui, have damaged habitat within the range of T. capillare. Invasive alien plant species, naturalized in dry and disturbed areas on all the main Hawaiian islands, compete intensively with Tetramolopium capillare. Especially important competitors are lantana (Lantana camara ), koa haole (Leucaena leucocephala ), and Natal redtop (Rynchelytrum repens ). Because Tetramolopium capillare grows in dry areas, fire is a threat to the species. Unrestricted collecting for scientific or horticultural purposes and substrate damage by people interested in seeing rare plants could result from the increased publicity generated by the federal listing of this species. The small number of individuals and populations of Tetramolopium capillare increases the potential for extinction from stochastic events. The limited gene pool may depress reproductive vigor, or an intense disturbance could destroy an entire population. Natural or human-induced erosion can destroy individual plants and habitat.
Conservation and Recovery
Tetramolopium capillare is listed as an endangered species at both the federal and state levels. Only 12 individuals survive, in two nearby populations on state land. Its critical habitat must be strictly protected from disturbances by humans. No grazing by cattle or other introduced mammals should be permitted, and alien plants should be reduced or eradicated from its habitat. The T. capillare should be propagated in captivity to produce stock for out-planting, and to establish additional populations in suitable habitat. Its populations should be monitored, and research undertaken into its biology and habitat needs.
U.S. Fish and Wildlife Service
Fish and Wildlife Office
260 Southeast 98th Avenue, Suite 100
Portland, Oregon 97266-1398
Telephone: (503) 231-6179
Fax: (503) 231-6195
U.S. Fish and Wildlife Service. 30 September 1994. "Endangered Status for the Plant Tetramolopium capillare (Pamakani)." Federal Register 59: 49860.