Weed Fire Risk Assessments

This page archives information about the fire risk and fire ecology of various non-native plants found in Hawai'i. More general information on the weed risks and ecology of non-native plants in Hawai'i is available from the Hawai'i Invasive Species Committee's Weed Risk Assessment database. Kevin Faccenda and Curt Daehler (both at the University of Hawai'i at Mānoa) developed a screening system focused on wildfire risk by asking land managers to assign a relative fire risk for weeds which are already naturalized in Hawai'i. This land manager expertise was then used to train a machine learning model to rank hundreds of other species based on plant traits and other information from the scientific literature. This research and the resulting fire risk model has been published in the journal Biological Invasions.

The Weed Fire Risk Database below assesses 360+ plant species for their fire-promoting traits and provides a computer model-generated fire risk score between 0 (no risk) and 1 (highest risk) for each plant species. A plant scoring above the threshold of about .3 should be considered higher risk and a potential concern as a wildfire promoter. The data below are presented as: (1) an interactive webpage, (2) an Excel file containing the data for all species, and (3) pdf fact sheets for each species. In addition to identifying plant species that are likely to pose high wildfire risk in Hawaii, this information may also be useful to predict post-fire responses, as available fire regeneration characteristics of each plant species are summarized.

The creation of this tool has been funded by the Pacific Islands Climate Adaptation Science Center (PICASC), a regional science center addressing the challenges presented by climate change and variability.

Note that the analysis doesn't account for a plant species' spatial distribution, population density, or distinct climate and ecosystem conditions (which can also influence fire risk). The fire risk of these species are mostly under "worst case" environmental conditions where the climate is dry enough to maintain fire, but wet enough to allow for plant growth and fuel accumulation. The fire risk ranking should not be taken as a stand-alone risk metric in prioritizing weed control efforts. Rather, this information may also be useful for determining if a newly discovered species poses a potential fire threat in wildland areas.

Viewing species as scientific names, to change to common names

Viewing species as common names, to change to scientific names

Note that for some species the scientific name is displayed if the plant has no English common names.
Also note that one species may occur multiple times on the list if it has multiple common names.

On this interactive factsheet you can filter species by islands, sort species by name or fire risk, and advance up and down the list of species using the previous and next buttons.

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This species is likely a fire risk in Hawai'i with a score of . This species was ranked by 49 managers on a scale of 'no risk', 'low risk', 'medium risk', or 'high risk'. The numerical score ranges from 0 to 1 with higher scores indicating more managers considered it a higher risk. A score of > 0.31 indicates high risk This species was ranked by our machine learning algorithm using the data presented below. A predicted score of > 0.34 suggests the plant is a high fire risk
Summary of fire ecology
Native habitat fire proneness
Fire promoting plant in its native range
Fire promoting plant in its introduced range*
Regenerates in burned areas after fire or by seed
Fire encourages regrowth of this plant
Reported flammable*
Relative is reported flammable*

*These values were used by the model to predict fire risk

Detailed summary of fire ecology
Native habitat fire proneness (In any part of the plant's native range is its habitat described as fire prone due to natural or human caused fires?)
Fire promoting plant in its native range (Does the species act as a major fuel source, increase fire severity, frequency, or modify fuel bed characteristics within its native range?)
Fire promoting plant in its introduced range (Same as Fire Promoting Native but within the species introduced range)
Regenerates after fire (Does the plant regrow after fire by any means? This includes resprouters, reseeders, and recruiters which dispersed into the area within approximately one year post fire)
Promoted by fire (Does the plant increase in abundance after a fire?)
Reported flammable (Is the species described as being flammable, being a major wildfire fuel, or high fire risk?)
Relative is flammable (Does a plant in the same genus meet the Reported Flammable criteria?)

Text in quotes are direct quotes from the source
Text in square brackets was added by the assessor to clarify what the source means
Text preceded by a # is comment by the assessor

The data presented were assembled from literature and database searches for each species using as much data as could be collected regarding the plant's fire ecology under natural conditions. Searches aimed to be exhaustive and consist of as much data as could be located in 2020. Our machine learning algorithm was trained on 49 species of plants which had their fire risk ranked by 49 managers in Hawai'i in November 2020. The model used a conditional random forest regression algorithm to predict scores for each species using the manager score as the response variable and the fire ecology traits of each plant as the predictor variables to generate a fire risk score. This trained model was then used to predict the fire risk for all species which were not ranked by managers. The model was calibrated such that it is 90% accurate at predicting high fire risk plants and 79% accurate at predicting low fire risk plants.

Fact sheet prepared by Kevin Faccenda ([email protected]) in November 2021. Data were prepared by in 2020.

This research was funded by the Department of the Interior Pacific Islands Climate Adaptation Science Center. The project described in this publication was supported by Grant or Cooperative Agreement No.G20AC00073 to Curt Daehler from the United States Geological Survey. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the Pacific Islands Climate Adaptation Science Center or the National Climate Adaptation Science Center or the US Geological Survey.

Please select a species to view its data

Download all data as an excel file.

PDF versions of the factsheets are available below. They contain the same data presented on this website. Use the button at the top of the page to change if these names are displayed as common or scientific names.

Acacia aulacocarpa
Acacia auriculiformis
Acacia confusa
Acacia mearnsii
Acacia melanoxylon
Acacia retinodes
Acacia robusta
Acokanthera schimperi
Adiantum macrophyllum
Adiantum trapeziforme
Aechmea bracteata
Aechmea cephaloides
Aechmea fulgens
Aglaomorpha rigidula
Agrostis hyemalis
Ailanthus altissima
Albizia adianthifolia
Albizia chinensis
Albizia procera
Allamanda schottii
Allophylus cobbe
Aloe vera
Alopecurus pratensis
Amaranthus polygonoides
Andropogon bicornis
Andropogon glomeratus
Andropogon virginicus
Annona cherimola
Anthoxanthum odoratum
Anthurium pentaphyllum
Anthurium schlechtendalii
Anthurium urbanii
Arctotheca calendula
Ardisia kusukusensis
Ardisia polysticta
Ardisia sieboldii
Ardisia solanacea
Arundo donax
Asparagus densiflorus
Asparagus falcatus
Banksia marginata
Barleria repens
Bartlettina sordida
Bastardia viscosa
Beaumontia multiflora
Begonia nelumbiifolia
Begonia serratipetala
Biancaea decapetala
Bidens pilosa
Blutaparon vermiculare
Bothriochloa bladhii
Bromus diandrus
Buddleja madagascariensis
Buddleja paniculata
Calathea zebrina
Calendula arvensis
Callicarpa macrophylla
Cananga odorata
Cardiospermum grandiflorum
Carduus pycnocephalus
Carissa macrocarpa
Carthamus tinctorius
Castilla elastica
Casuarina equisetifolia
Cedrela odorata
Cenchrus ciliaris
Cenchrus clandestinus
Cenchrus elegans
Cenchrus longisetus
Cenchrus polystachios
Cenchrus purpureus
Cenchrus setaceus
Cenchrus tribuloides
Chromolaena odorata
Chrysobalanus icaco
Cirsium arvense
Cissus rhombifolia
Clerodendrum myricoides
Clitoria ternatea
Coccinia grandis
Cordia sebestena
Cornus kousa
Cortaderia jubata
Cortaderia selloana
Costus malortieanus
Cotoneaster pannosus
Crassula multicava
Cryptomeria japonica
Cryptostegia grandiflora
Cryptostegia madagascariensis
Cupressus lusitanica
Cyclophyllum barbatum
Cynanchum gerrardii
Cyperus aggregatus
Cyperus fulvus
Cytisus scoparius
Dendrobium cv. Jaquelyn Thomas
Dendrobium discolor
Dendrobium lineale
Dendrobium rhombeum
Deschampsia cespitosa
Dichanthium annulatum
Digitaria abyssinica
Digitaria eriantha
Digitaria insularis
Dimerocostus strobilaceus
Disakisperma dubia
Dischidia ovata
Distichlis spicata
Dolichandra unguis-cati
Duranta erecta
Echinochloa cruspavonis
Ehrharta calycina
Ehrharta stipoides
Elaeocarpus angustifolius
Elaeocarpus serratus
Eleocharis olivacea
Elymus repens
Enterolobium cyclocarpum
Entolasia marginata
Eragrostis ciliaris
Eragrostis curvula
Eragrostis dielsii
Eragrostis superba
Eragrostis tenuifolia
Erica lusitanica
Erodium cicutarium
Erythrina speciosa
Eucalyptus cinerea
Eucalyptus globulus
Eucalyptus goniocalyx
Eucalyptus paniculata
Eucalyptus pulchella
Euphorbia antiquorum
Euphorbia ingens
Euphorbia leucocephala
Falcataria moluccana
Festuca bromoides
Ficus pumila
Ficus religiosa
Flacourtia indica
Flacourtia zippelii
Flemingia macrophylla
Florestina tripteris
Flueggea virosa
Frangula californica
Fraxinus uhdei
Fumaria officinalis
Furcraea foetida
Galium parisiense
Gliricidia sepium
Grevillea robusta
Grewia truncata
Guaiacum sanctum
Gutierrezia sarothrae
Guzmania monostachia
Hedypnois rhagadioloides
Heteranthera reniformis
Heterotheca grandiflora
Hibiscus acetosella
Hibiscus makinoi
Holcus lanatus
Homalanthus populneus
Homalocladium platycladum
Hyparrhenia hirta
Hyparrhenia rufa
Hypericum canariense
Hypoestes phyllostachya
Imperata cylindrica
Indigofera suffruticosa
Inga feuillei
Ipomoea corymbosa
Ischaemum ciliare
Jasminum fluminense
Jasminum multiflorum
Jatropha gossypiifolia
Jatropha multifida
Justicia gendarussa
Justicia secunda

Kalanchoe crenata
Kalanchoe daigremontiana
Kalanchoe fedtschenkoi
Kalanchoe lateritia
Kalanchoe laxiflora
Kalanchoe rotundifolia
Kalanchoe x houghtonii
Lantana camara
Lantana montevidensis
Laportea aestuans
Lappula occidentalis
Leea indica
Leonotis nepetifolia
Leptochloa panicea
Leptospermum laevigatum
Lespedeza cuneata
Leucaena leucocephala
Leucanthemum x superbum
Licuala spinosa
Linaria purpurea
Liriodendron tulipifera
Livistona chinensis
Lolium arundinaceum
Lolium multiflorum
Lolium perenne
Lolium pratense
Lonicera japonica
Ludwigia hyssopifolia
Lygodium japonicum
Macaranga tanarius
Maclura tinctoria
Macroptilium lathyroides
Macrotyloma axillare
Markhamia lutea
Matricaria discoidea
Megathyrsus maximus
Melaleuca armillaris
Melaleuca quinquenervia
Melia azedarach
Melicope elleryana
Melilotus alba
Melinis minutiflora
Melinis nerviglumis
Melinis repens
Mesosphaerum pectinatum
Miconia crenata
Mimusops elengi
Miscanthus floridulus
Morella cerifera
Morella faya
Moringa stenopetala
Myrciaria floribunda
Nassella cernua
Nassella tenuissima
Neolitsea cassia
Nerium oleander
Neustanthus phaseoloides
Norantea guianensis
Nymphoides aquatica
Ochna serrulata
Ochna thomasiana
Oenothera curtiflora
Oenothera speciosa
Opuntia ficus-indica
Origanum vulgare
Pachira aquatica
Paederia foetida
Panicum virgatum
Parkia timoriana
Parkinsonia aculeata
Parthenium hysterophorus
Paspalum arundinaceum
Paspalum lindenianum
Paspalum longifolium
Paspalum mandiocanum
Paspalum pilosum
Paspalum unispicatum
Paspalum virgatum
Passiflora suberosa
Passiflora tarminiana
Pelargonium x domesticum
Peniocereus hirschtianus
Pereskia aculeata
Perilla frutescens
Phenax hirtus
Philodendron scandens
Phyllanthus reticulatus
Phyllostachys aurea
Phytolacca dioica
Pilea hyalina
Pilea spruceana
Pimenta racemosa
Pinus elliottii
Pinus jeffreyi
Pinus patula
Pinus pinaster
Pinus radiata
Piper aduncum
Piper auritum
Piper divaricatum
Piptatherum miliaceum
Pittosporum senacia
Pluchea carolinensis
Polyalthia suberosa
Polyscias filicifolia
Porophyllum ruderale
Proboscidea louisianica
Procris pedunculata
Prosopis juliflora
Prosopis pallida
Pseudognaphalium attenuatum
Pterocarpus indicus
Pyrrosia longifolia
Quisqualis indica
Rauvolfia vomitoria
Rhynchospora inexpansa
Ricinus communis
Rubus discolor
Rubus glaucus
Rubus niveus
Rubus rosifolius
Saccharum spontaneum
Sagittaria platyphylla
Salsola tragus
Salvia procurrens
Salvinia molesta
Schefflera insularum
Schefflera roxburghii
Schinus terebinthifolius
Schizachyrium condensatum
Scleranthus annuus
Selaginella pallescens
Selaginella willdenowii
Senecio madagascariensis
Senna surattensis
Sesbania grandiflora
Setaria sphacelata
Silene armeria
Silybum marianum
Smilax bona-nox
Solanum mammosum
Sophora tomentosa
Sorghum spp.
Sorghum x drummondii
Spartium junceum
Spermacoce alata
Spermacoce ocymifolia
Sporobolus piliferus
Stephania japonica
Stylosanthes guianensis
Swietenia mahagoni
Synadenium grantii
Tabernaemontana pandacaqui
Tagetes minuta
Tephrosia pumila
Terminalia bellirica
Tetrapanax papyrifer
Tetrastigma voinierianum
Thunbergia vogeliana
Tibouchina herbacea
Tillandsia juncea
Tillandsia usneoides
Tithonia rotundifolia
Trichospermum richii
Trimezia steyermarkii
Typha latifolia
Ulex europaeus
Urochloa brizantha
Urochloa decumbens
Urochloa mutica
Urtica urens
Vachellia farnesiana
Vanilla planifolia
Verbesina turbacensis
Viola hederacea
Washingtonia filifera
Washingtonia robusta
Werauhia gladioliflora
Yucca aloifolia
Ziziphus mauritiana

African milkbush
air plant
aloe vera
aloe yucca
Andean raspberry
Angleton grass
antique spurge
antler orchid
argyle apple
asparagus fern
Australian bluestem
Australian tea tree
Australian violet
banana poka
Barbados gooseberry
Barundi dropseed
basket fern
bay rum tree
bella sombra
Beringian hairgrass
big floatingheart
black wattle
Blackwood acacia
blue creeper
blue gum
blue marble tree
blue-flowered clerodendrum
bo tree
bordered panic grass
bracelet honey myrtle
Broad-leaved paspalum
brome fescue
broom snakeweed
burgundy giant
bush allamanda
Butterfly bush
butterfly pea
cabbage tree
California fan palm
California grass
candelabra tree
castor bean
cat's-claw climber
chestnut vine
Chinese fan palm
Chinese lespedeza
Chinese rice-paper plant
Chinese waterberry
Christmas berry
climbing fig
coco plum
comb hyptis
common cattail
common ironwood
common kalanchoe
common thatching grass
common velvet grass
coral plant
cotton-leaved jatropha
couch grass
cranberry hibiscus
creeping thistle
Delta arrowhead
devil weed
drug fumitory
dune sandbur
dwarf bamboo
dwarf nettle
dyer's mulberry
Earleaf acacia
Easter lily vine
elephant grass
fairy crassula
false buttonweed
false ragweed
false sakau
feather top fountain grass
feathery pennisetum
fedtschenkoi kalanchoe
fern-leaf aralia
field marigold
Formosan koa
fountain grass
freckle face
German knotweed 
giant maidenhair
golden dewdrop
governor's plum
grape ivy
gray ironbark
Guiana chestnut
Guinea grass
gulf cockspur grass
heart-leaf philodendron
hill raspberry
Himalayan blackberry
holywood lignum vitae
Houghton's hybrid
huehue haole
ice-cream bean tree
Indian jujube
inflated-scale flatsedge
Italian ryegrass
Italian thistle
ivy gourd
Japanese cedar
Japanese climbing fern
Japanese honeysuckle
jaragua grass
Jeffrey pine
Jelecote pine
Jerusalem thorn
Kariba weed
kidneyleaf mudplantain
Kikuyu grass
koa haole
Koster's curse
Largeleaf Maidenhair fern
licuala palm
lily-pad begonia

lion's ear
little bluestem
long-leaved paspalum
Madagascar rubber vine
maile pilau
mallee lovegrass
maritime pine
Martha Washington geranium
Mauritius hemp
meadow foxtail
meadow ricegrass
Mexican cypress
Mexican fan palm
Mexican feathergrass
Mexican sunflower
Mexican tree daisy
Mickey Mouse plant
Mickey Mouse plant
milk thistle
Milky Widows's Thrill
molasses grass
Moluccan albizia
Monterey pine
natal plum
Natal redtop
New Guinea wattle
Nile tulip
nipple fruit
Okinawan Hibiscus
onespike paspalum
Pacific island silvergrass
Pale Spikemoss
pampas grass
pampas grass
panama rubber tree
pangola grass
parasol leaf tree
perennial horse gram
perennial ryegrass
perennial veldtgrass
pheasants tail 
pineapple weed
pink euodia
pink ruellia
poison devil's-pepper
Portuguese heath
prickly pear
purple toadflax
Purple torch
Rangoon creeper
red-hot poker
ribbon bush
ripgut grass
rubber vine
ruby grass
Russian thistle
saw greenbrier
scaly hawkbit
scarlet cordia
Scotch broom
scrambled eggs
Shasta daisy
shoebutton ardisia
signal grass
silk oak
silver banksia
silverleaf cotoneaster
slash pine
smoke bush
snake vine
South African pigeon grass
southern wax myrtle
Spanish broom
Spanish cedar
Spanish moss
Spanish needle
Spanish reed
spiked pepper
Splendid thorn
St. John's wort
star jasmine
star jasmine
stepladder plant
sticky florestina
Sudan grass
sweet vernalgrass
Sweet William catchfly
sword grass
taperd cudweed
telegraph weed
trailing lantana
tree bean
tropical ash
tropical kudzu
tulip tree
unicorn plant
vegetable hummingbird
viscid mallow
walking iris
wall bedstraw
water wattle
watermelon dischidia
West Indian mahogany
West Indian tufted air plant
West Indian woodnettle
Western Stickseed
white evening primrose
white peppermint
white siris
white sweet clover
wild bean
wild cane
Willdenow's spikemoss
willow-leaved justicia
Wilman lovegrass
Winter bentgrass
yellow necklacepod
Yerba Porosa
zebra plant