Silene Alexandri

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Silene alexandri

No Common Name

ListedOctober 8, 1992
FamilyCaryophyllaceae (Pink)
DescriptionTerrestrial shrub or tree with short leaves, leaf stalks, and flower stalks.
HabitatRemnant dry forest and shrubland.
ThreatsHabitat disturbance and predation by wild, feral, or domestic animals, fire, low numbers.


Silene alexandri is an erect perennial herb in the pink family that grows 1-2 ft (0.3-0.6 m) high; its stem is woody at the base. The narrow, elliptic, and glabrous leaves are 1.2-2.5 in (3-6.5 cm) long, 0.2-0.6 in (0.5-1.5 cm) wide, and have a ciliated fringe along the margins. The flowers are arranged in open clusters with stalks 0.4-0.7 in (1-1.8 cm) long. The five-lobed, 10-veined, and tubular calyx is 0.7-1 in (1.8-2.5 cm) long, while the five white, deeply lobed, and clawed petals extend about 0.2 in (0.5 cm) beyond the calyx. The capsule is 0.6 in (1.5 cm) long, but seeds have never been observed. The hairless stems, flowering stalks, sepals, and the larger flowers with white petals distinguish this species from other members of the genus.


The two known populations of S. alexandri are found in remnant dry forest and shrubland at an elevation of 2,000-2,500 ft (610-760 m). Associated plant species include 'a'ali'i, 'ohi'a, pukiawe, and uluhe.


Endemic to Hawaii, S. alexandri was known from historical occurrences at Makolelau and Kamalo on East Molokai. There were only two extant populations of this species in 1992, consisting of approximately 35 individuals at Makolelau and Kawela on privately owned land.


Feral goats continue to degrade the habitat of S. alexandri and pose a serious threat to the remaining populations. Predation of this species by goats and cattle may possibly occur. Fire is also an imminent threat. Because of the small number of individuals and their severely restricted distribution, extinction from random naturally occurring events is a real threat.

Conservation and Recovery

S. alexandri seeds have been collected and propagated by the National Tropical Botanical Garden.


U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121

U. S. Fish and Wildlife Service Pacific Remote Islands Ecological Services Field Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-1201
Fax: (808) 541-1216


U. S. Fish and Wildlife Service. 8 October 1992. "De-termination of Endangered or Threatened Status for 16 Plants from the Island of Molokai, Hawaii." Federal Register 57 (196): 46325-46340.