|Scaevola subsp. var.|
Scaevola is a genus of flowering plants in the Goodenia family, Goodeniaceae. It consists of more than 130 tropical species, with the center of diversity being Australia and Polynesia, including Hawaii.
Common names for Scaevola species include scaevolas, fan-flowers, half-flowers, and naupaka, the plant's Hawaiian name. The flowers are shaped as if they have been horizontally cut in half. Consequently, the generic name means "left-handed" in Latin. Many legends have been told to explain the formation of the naupaka's unique half flowers. In one version a woman tears the flower in half after a quarrel with her lover. The Gods, angered, turn all naupaka flowers into half flowers and the two lovers remained separated while the man is destined to search in vain for another whole flower.
Scaevola is the only Goodeniaceae genus that is widespread outside of Australia. In at least six separate dispersals, about 40 species have spread throughout the Pacific Basin, with a few reaching the tropical coasts of the Atlantic and Indian Oceans.
The Hawaiian Islands are home to ten Scaevola species, nine of which are endemic. Eight of the indigenous species are the result of a single colonization event. Scaevola glabra and Scaevola taccada arrived separately to produce a total of three colonizations of Hawaii by Scaevola. Some of the endemic species are of hybrid origin. 
Beach Naupaka (Scaevola taccada synonym S. sericea) occurs throughout the Pacific and Indian Oceans and is an invasive species in Florida, USA, and in some islands of the Caribbean including the Cayman Islands and the Bahamas. Beachberry or Inkberry (Scaevola plumieri) is widespread in the tropical Americas and Africa; however, it is becoming rarer in areas where S. taccada is displacing native coastal plants.
Most Australian Scaevola have dry fruits and sprawling, herbaceous to shrubby habits. By contrast, nearly all species outside Australia have shrub habits with fleshy fruit making dispersal by frugivores easy.
|Standard Cyclopedia of Horticulture|
Scaevola (Latin, a diminutive of scaeva, the left-handed, probably alluding to the form of the corolla). Goodeniaceae. Herbs, subshrubs, or shrubs suitable for greenhouse culture: lvs. alternate: fls. solitary between 2 bracteoles, sessile or pedunculate, axillary or the peduncles dichotomously branched with a fl. in each fork; calyx-tube adnate, limb usually very short; corolla oblique, the tube slit open to the base, lobes nearly equal; ovary wholly inferior or rarely the summit free, 2-celled with 1 erect ovule in each cell, or 1-celled with 1 or 2 erect ovules: fr. indehiscent, more or less succulent. — About 83 species, mostly Australian, but also the Pacific islands, Asia, and one each in Afr. and the W. Indies. A few of the species which have been cult. are: S. attenuata, R. Br., with broadly lanceolate lvs. and blue fls. in terminal leafy spikes. Austral. B.M. 4196. S. cuneiformis, Labill., with obovate lower and oblong-cuneate upper lvs. and blue fls. in a long interrupted spike. Austral. S. suaveolens, R. Br., a prostrate. or decumbent hardy perennial or subshrub with petiolate lvs. obovate to oblong-spatulate, and blue fls. in interrupted terminal hirsute spikes. Aug. Austral. CH
Pests and diseases
- Main article: List of Scaevola species
- Scaevola aemula R.Br. – Fairy Fan-flower or Common Fan-flower (Southern Australia)
- Scaevola amblyanthera F.Muell.
- Scaevola brookeana F.Muell.
- Scaevola chamissoniana Gaudich. Naupaka kuahiwi (Hawaii)
- Scaevola chanii K.M.Wong (Malaysia)
- Scaevola collaris F.Muell.
- Scaevola coriacea Nutt. – Dwarf Naupaka (Hawaii)
- Scaevola crassifolia Labill. – Thick-leaved Fan-flower (Australia)
- Scaevola enantophylla F.Muell.
- Scaevola floribunda A.Gray (Fiji)
- Scaevola gaudichaudiana Cham. – Mountain Naupaka, Naupaka kuahiwi (Hawaii)
- Scaevola gaudichaudii Hook. & Arn. – Ridgetop Naupaka (Hawaii)
- Scaevola hookeri (de Vriese) F.Muell. ex Hook.f. – Creeping Fan-flower or Alpine Fan-flower
- Scaevola kilaueae O.Deg. – Huahekili uka ([[Hawaii (island)|island of HawaiTemplate:Okinai]])
- Scaevola muluensis K.M.Wong (Malaysia)
- Scaevola macrophylla
- Scaevola oldfieldii F.Muell.
- Scaevola oxyclona F.Muell.
- Scaevola parvifolia F.Muell. ex Benth.
- Scaevola phlebopetala F.Muell.
- Scaevola plumieri (L.) Vahl – Beachberry, Waxy Bush, "inkberry" (Pantropical)
- Scaevola porocarya F.Muell.
- Scaevola procera Hillebr. – Forest Naupaka, Naupaka kuahiwi ([[Molokai|MolokaTemplate:Okinai]] and KauaTemplate:Okinai in Hawaii)
- Scaevola ramosissima
- Scaevola socotraensis H.St.John (Yemen)
- Scaevola taccada (Gaertn.) Roxb. – Beach Naupaka, Naupaka kahakai (Hawaiian); ngahu (Tongan) (Pantropical)
- Scaevola verticillata Leenh. (Malaysia)
- ↑ Hammer, Roger. 1998. Postcards from Paradise: Separated Lovers and the Beach Naupaka. >PDF
- ↑ Offshore Islet Restoration Committee. Undated. Species - Plants > Selected Plants Found on Hawaii's Offshore Islets. 
- ↑ Dianella G. Howarth and David A. Baum. 2005. "Genealogical evidence of homoploid hybrid speciation in an adaptive radiation of Scaevola (Goodeniaceae) in the Hawaiian Islands". Evolution 59(5):948-961.
- ↑ DaCosta-Cottam, M., Olynik, J., Blumenthal, J., Godbeer, K.D., Gibb, J., Bothwell, J., Burton, F.J., Bradley, P.E., Band, A., Austin, T., Bush, P., Johnson, B.J., Hurlston, L., Bishop, L., McCoy, C., Parsons, G., Kirkconnell, J., Halford, S. and Ebanks-Petrie, G. 2009. Cayman Islands National Biodiversity Action Plan 2009. Cayman Islands Government. Department of Environment.
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963