Vigna marina (Burm. f.) Merr.
Plant Family
Fabaceae (Pea or legume family)
Preferred Binomial Name
Vigna marina (Burm. f.) Merr.
Synonymous Binomial Names
Dolichos luteus Sw., Phaseolus marinus Burm., Phaseolus obovatus Gagnep., Scytalis anomala E.Mey., Scytalis retusa E.Mey.,Vigna anomala Walp., Vigna lutea (Sw.) A.Gray, Vigna repens var. lutea (Sw.) Kuntze, Vigna retusa (E.Mey.) Walp. (CABI 2019).
Subspecies
Two subspecies are known in Africa: subsp. marina and subsp. oblonga (Benth.) (Aguilar 2016).
Common (Vernacular) Names
English: beach pea, beach bean, dune bean, field bean, notched cowpea field bean, notched cowpea, sea bean, shore bean
Indonesia: kacang laut (Java), rerenge makenti (Sulawesi), fofuo dowongi (Ternate)
Malaysia: kacang laut
Philippines: pataning-dagat (PROSEA 2019).
Hawaiian Names
Lemuomakili, Mohihihi, Nanea, Nenea, ʻŌkolemakili, Pūhili, Pūhilihili, Wahine ʻōmaʻo (UH 2019).
Plant Characteristics
Endemicity. Indigenous to the major Hawaiian Islands and pantropical in coastal areas on beaches and dunes in East Africa, some parts of the Atlantic and Caribbean and throughout the Pacific. It is probably native to these areas and may have been introduced in some local areas by intentional or accidental human intervention (CABI 2019).
Growth Habit. A short-lived, perennial, non-woody, prostrate, wide spreading vine (liana) that may grow 3-4 meters long.
 Growth Habit of Vigna marina |
Leaves. The leaves are from 4 to 10 cm long, trifoliate, alternately arranged, oval to oblong in shape, green to light green in color, smooth-edged with pointed tips with variable amounts of coarse hairs.
Flowers. The plant bares trifoliate, yellow green or bright yellow, unscented pea-like flowers on stalks about 2 to 5 cm long. These may appear unnoticed under the leaves. In our area beach peas bloom sporadically throughout the year, particularly after periods of rainfall.
 Flower Cluster of Vigna marina |
 Flower of Vigna marina |
Fruit and Seeds. The seeds grow in pods similar to those of small garden peas. On ripening the pods turn from light green to brown or black and when fully ripe the pods open (dehisce) and twist, discharging brown seeds. The coastal distribution of this species seems to be related to the inflated, non-shattering pods, which may float from coast to coast (Aguilar 2016).
The average weight of seeds collected from dry pods at our facility is 0.1 gram.
 Unripe Seed Pods of Vigna marina |
 Dehiscing Pods of Vigna marina Dropping Seeds |
 Seeds of Vigna marina |
Nitrogen Fixation. As is common for many legumes, Vigna marina has root nodules inhabited by rhizobia that fix atmospheric nitrogen, which can be used by the host plant and other plants in the surrounding soil or sand. Nodulation does not require inoculation by a specific rhizobium. Pantropical legumes such as nanea have the rhizobia Bradyrhizobium and Sinorhizobium that have wide geographic distributions. Refer to the publication by Bamba et al. 2016 for detailed information.
Composition. The approximate composition of V. marina per 100 g fresh material is: water 66 g, protein 3 g, carbohydrates 24 g, fat 1 g, fibre 4 g, and ash 2 g (Aguilar 2016).
Conservation Status
This species is not threatened or endangered.
CITES Listing: Vigna marina was not found on CITES Appendices I, II or III (CITES 2019).
U.S. Endangered Species Act Listing Status: This species is not listed (FWS 2018a).
IUCN Listing: No assessment of this species was found on the IUCN Red List of Threatened Species™ [IUCN 2019].
Related Hawaiian Species
The Oʻahu cowpea (Vigna o-wahuensis) is an endangered species endemic to Hawaii (USFWS 2019b). Another indigenous species, the wild pea (Vigna adenantha), was found on Oʻahu (Diamond Head) and Hawaiʻi Island but has not been seen since the early 1850’s (UH 2019).
Uses
Vigna marina has many uses as a food, medicine, cover crop, ground cover and in landscaping.
Use as Food. All parts of the plant are edible. The seeds can be cooked as other dry peas and the leaves can be eaten as a vegetable if they are thoroughly cooked. In Australia the thicker roots may be consumed after roasting (Aguilar 2016). The uncooked immature peas taste similar to those of the common garden pea (Pisum sativum) with a more bitter aftertaste.
This plant is closely related to several other species of peas and beans that are widely used as food.
Livestock feed. Livestock will eat the plant when cut as green forage (Aguilar 2016).
Traditional Medicinal Uses. In Papua New Guinea fresh leaves are crushed with lime and water, squeezed and the juice is consumed as a remedy for stomach aches. Leaf juice is given to children as a treatment for asthma and the leaves are heated over a fire and then used as a poultice on sores (WHO 2009) cited in Fern (2019). Similarly, in early Hawaii, the leaves, stalk, midrib (kua), and stems were pounded until soft and applied to wounds and hēhē (boils, running sore, ulcers), [Kaʻaiakamanu KM (undated) cited in UH (2019)].
Cover Crop. Vigna marina is promising for use as a cover crop in saline soils and has been tested in mixed plantings with grass (Aguilar 2016). Arbuscular mycorrhizal fungi dominant near the sea are adapted to salt-stressed environment to alleviate the salt stress of host plants (Yamato, Ikeda and Iwase 2008).
Landscaping. The characteristics of this species make it well suited for multiple landscaping uses in tropical coastal areas:
- It is highly tolerant of salty soils and windy conditions and is used as an accent plant, ground cover, trellis or fence climber and for erosion control and dune stabilization UH 2019 et al.).
- As a nitrogen-fixing plant it will provide other plants growing in the area with a ready source of free fertilizer. This vine is great for open, sunny areas as a groundcover and especially good for beach front properties.
- It is commercially available and a potentially important plant for supporting pollinators in the Pacific Islands area. It may be used as a pollinator-friendly plant in marginal lands unsuitable for planting trees (Xerces 2014).
Cultivation
The plant is typically harvested from the wild for use as food and medicine (Fern 2019).
Cultivation in Hawaiʻi.
In Hawaiʻi this plant is primarily cultivated for landscaping purposes and is especially well suited for beach front properties. It can be grown outside its normal range and in soil types not typical of coastal environments. The plants at our facility shown in the photos were planted from purchased nursery stock and are growing at an elevation of about 900 feet, well above their natural range and about three miles from the nearest shoreline. Here we have no sand and shallow cinder soils over volcanic rock.
Cultivation Elsewhere. The plant is cultivated as a food crop in the Maldives (Fern 2019).
Propagation
Seeds. The plant is most commonly propagated from seeds. Light scarification or soaking the seeds in water for 24 hours may speed germination. No inoculations are required for nodulation and nitrogen fixation.
Cuttings. Nanea can be propagated from cuttings quickly and easily. Make the cuttings from the woodier areas of the plant and place them in a medium that drains easily while retaining moisture such as a 50 percent combination of perlite and vermiculite, or a mix of 3 parts perlite to 1 part potting mix. Dipping the cuttings in a rooting hormone (numbers 3-8) before planting may improve results.
Growing Instructions. Refer to these references for growing instructions: [HOK (Undated), Duff (2015) and UH (2019)].
Improved Cultivars
We are unaware of any improved cultivars of this species and it is unlikely that any substantial germplasm collections of V. marina are being maintained. Crosses of Vigna marina with V. luteola (Jacq.) Bentham have produced fertile hybrids. Because this species is well adapted to dry, saline soils it may be useful in breeding programs for improvement of other Vigna species (Aguilar 2016) and these may be important as crops. Genetic linkage maps of V. marina ssp. oblongata have been made and the genetic markers responsible for salt tolerance have been identified. This data may facilitate the transfer of the salt tolerance allele from V. marina ssp. oblongata into related Vigna crops (Chankaew et al 2014).
Since the habitats of wild Vigna species are so diverse their genomes could also harbor various genes responsible for environmental stress adaptation and these could lead to other innovations in agriculture. In a recent study of gene bank accessions, some of the Vigna accessions were seemed to have novel genetic resources (Takahashi et al. 2016).
Pests and Diseases
Ants. In our area the little black ant (Monomorium minimum) appears to be highly associated with this plant and it is frequently found on the pods. The nature of the association is unclear; they may feed on nectar, or spread and/or tend insects such as aphids and scale that sometimes infest the plant.
Seed Weevils. Weevils attack maturing beach pea seeds in the pods. If production of seeds is intended they should be harvested as soon as the pods begin to turn brown to minimize weevil damage. Infested seeds and pods should be destroyed. Unless they are going to be planted immediately, the seeds should be dried and refrigerated or frozen to kill the weevils and prevent re-infestation.
Invasive Pests Affecting Legumes. Stink bugs (Coptosome xantogramma) and white peach scale (Pseudaulacaspis pentagona) are two invasive species that are serious pests of native and crop species of legumes in our immediate area. We have not observed these pests on beach peas grown in close proximity to other affected legumes.
Other Pests. The plants are occasionally attached by aphids, leaf miners, scales and spider mites. These seldom do significant damage.
Diseases. We have not observed diseases affecting this species. It is a natural host of Cucumber Mosaic Virus (CMV) in Taiwan (Deng et al 2010), Bean common mosaic virus in the Solomon Islands (Brunt 1987) and Alfalfa mosaic virus or Beet western yellows virus in Australia (Büchen-Osmond 2002). Plants affected by CMV in Taiwan showed severe mosaic and chlorotic ringspots on their foliage.
Invasiveness Potential
Vigna marina can form dense stands along shorelines preventing the establishment of other native plant species. In Tuvalu, it may interfere with the establishment of Cocos nucifera (coconut) and Artocarpus altilis (breadfruit) on plantations. Reports associated with the invasiveness of this species are infrequent and V. marina is considered only a minor invasive. (CABI 2019).
In our growing area on a sloping hillside with thin, dry soil predominantly composed of volcanic cinders, the beach pea grows rapidly and will climb on ornamental plants such as croton (Codiaeum variegatum), hibiscus and philodendron, and also on native species such as Palomele hawaiiensis (hala pepe) and Scaevola taccada (naupaka). The vines can deny light and choke out other desirable species. Unwanted growth can be removed by trimming without harming the plant.
Hawai‘i-Pacific Weed Risk Assessment (HPWRA) Program. No assessment of this species was found in HPWRA records (HPWRA 2019).
Global Invasive Species Database Listing. This species was not found in the database (GISD 2018).
 Vagna marina choking out Hala Pepe (Pleomele hawaiiensis), an Endangered Native Hawaiian Plant |
 Vigna marina on Croton (Ornamental) and Naupaka (Native Species) |
Toxicity and Precautions
There are no known hazards associated with this plant (Fern 2019).
Plants and Seeds for Sale
Availability
Seeds. Packets of seeds available in our online store. These are from cultivated plants on our property. We do not offer seeds collected from the wild. Our seeds are cleaned, dried and frozen to destroy pests and for long term storage. Seeds of this species should be viable for several years if stored frozen or under refrigeration.
 Seeds of Vigna marina Close Up |
Nursery Stock. We may provide fresh cuttings for delivery in Hawaii only. Please contact us if you are interested in these.
Shipping Information
All seeds shipped to customers outside Hawaii island must be inspected by the Hawaii Department of Agriculture or USDA as applicable. We transport small shipments to the distant inspection facilities about every two weeks and then they are shipped as First Class Mail or international mail. See our Terms and Conditions for information on shipments to international destinations.
References
Aguilar NO. 2016. PROSEA (Plant Resources of South-East Asia) 2019. Vigna marina (PROSEA). https://uses.plantnet-project.org/en/Vigna_marina_(PROSEA) [accessed 17 August 2019].
Bamba M, Nakata S, Aoki S, Takayama K, Núñez-Farfán J, Ito M, Miya M, Kajita T. 2016. Wide distribution range of rhizobial symbionts associated with pantropical sea-dispersed legumes. Antonie Van Leeuwenhoek. 109(12):1605-1614.
Brunt AA. 1987. Surveys for Plant Viruses and Virus Diseases in Solomon Islands. FAO, Rome, 1987. Cited in Deng et al (2010).
Büchen-Osmond, C ed. 2002. Viruses of Plants in Australia. Retrieved from http://www.ictvdb.rothamsted.ac.uk/Aussi/aussi.htm. Cited in Deng et al (2010).
CABI(CAB International) 2019. Invasive Species Compendium. Datasheet for Vigna marina (Beach bean). https://www.cabi.org/isc/datasheet/121982#tosummaryOfInvasiveness [accessed 17 August 2019].
Chankaew S, Isemura T, Naito K, Ogiso-Tanaka E, Tomooka N, Somta P, Kaga A, Vaughan DA, Srinives P. 2014. QTL mapping for salt tolerance and domestication-related traits in Vigna marina subsp. oblonga, a halophytic species. Theor Appl Genet. 127(3):691-702. doi: 10.1007/s00122-013-2251-1. Epub 2013 Dec 27. PMID: 24370961.
CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Appendices I, II, and III valid from 4 October 2017. https://www.cites.org/eng/app/appendices.php [accessed 17 August 2019].
Deng TC, Tsai CH, Tsai HL, Liao JY, Huang WC. 2010. First Report of Cucumber mosaic virus on Vigna marina in Taiwan. Plant Dis. 94(10):1267. doi: 10.1094/PDIS-06-10-0459. https://apsjournals.apsnet.org/doi/abs/10.1094/PDIS-06-10-0459 [accessed 17 August 2019].
Duff D. 2015. Plant nanea for a great ground cover. West Hawaii Today. September 6, 2015. https://www.westhawaiitoday.com/2015/09/06/features/plant-nanea-for-a-great-ground-cover/ [accessed 17 August 2019].
Fern. K. 2019. Useful Tropical Plants. Vigna marina. http://tropical.theferns.info/viewtropical.php?id=Vigna+marina [accessed 17 August 2019].
FOC (Flora of China) 2019. Vigna marina. FOC Vol 10, Pages 255-256. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242354370 [accessed 17 August 2019].
FWS (U.S. Fish and Wildlife Service). 2019a. Endangered Species Home. Search Endangered Species Database. https://www.fws.gov/endangered/ [accessed 17 August 2019].
FWS (U.S. Fish and Wildlife Service). 2019b. ECOS. Environmental Conservation Online System. Species Profile for Vigna o-wahuensis. https://ecos.fws.gov/ecp0/profile/speciesProfile?sId=8445 [accessed 17 August 2019].
GISD (Global Invasive Species Database) 2019. Downloaded from http://www.iucngisd.org/gisd/search.php on 17 August 2019.
HOK (Hui o Koʻolaupoko). Undated. Hui o Koʻolaupoko Plant Propagation and Care Manual. https://www.huihawaii.org/uploads/1/6/6/3/16632890/plant_foster_parent_handbook_final_draft_for_pdf.pdf [accessed 17 August 2019].
HPWRA (Hawaii-Pacific Weed Risk Assessment). 2019. https://sites.google.com/site/weedriskassessment/home [accessed 17 August 2019].
IUCN (International Union for Conservation of Nature). 2019. Version 2012-1. The IUCN Red List of Threatened Species™. http://www.iucnredlist.org/search [accessed 17 August 2019].
Kaʻaiakamanu KM. (undated cross reference). Native Hawaiian Medicine–Volume III” by The Rev. Kaluna M. Kaʻaiakamanu, page 80. Cited in UH (2019).
Takahashi Y, Somta P, Muto C et al. 2016. Novel genetic resources in the genus Vigna unveiled from gene bank accessions. PLoS One, 11, e0147568.
UH (University of Hawaii). 2019. Native Plants Hawaii. Vigna marina. http://www.nativeplants.hawaii.edu/plant/view/Vigna_marina [accessed 17 August 2019].
WHO (World Health Organization) 2009. Medicinal Plants in Papua New Guinea. ISBN 978-92-9061-249-0. Cited in Fern (2019).
Xerces (The Xerces Society for Invertebrate Conservation). 2014. Habitat Planting for Pollinators Pacific Islands Area. http://www.xerces.org/wp-content/uploads/2015/07/PollinatorHabitat_PacificIslandsArea_Nov2014_web.pdf [accessed 17 August 2019].
Yamato, M, Ikeda, S and Iwase, K 2008. Community of arbuscular mycorrhizal fungi in a coastal vegetation on Okinawa island and effect of the isolated fungi on growth of sorghum under salt-treated conditions. Mycorrhiza. 18: 241. https://doi.org/10.1007/s00572-008-0177-2
Yamamoto T, Tsuda Y, Takayama K, Nagashima R, Tateishi Y, Kajita T. 2019. The presence of a cryptic barrier in the West Pacific Ocean suggests the effect of glacial climate changes on a widespread sea-dispersed plant, Vigna marina (Fabaceae). Ecol Evol. 15:8429-8440. doi: 10.1002/ece3.5099. PubMed PMID: 31410251; PubMed Central PMCID: PMC6686344.
This page was last updated on 18 August 2019.