Non-Native / Invasive Plants in Hawaiʻi: My Plant ID Guide
Unlike my post about native Hawaiian plants, these are the plants I’ve come across that are either non-native and/ or invasive species in Hawaiʻi.
That being said, my native Hawaiian plant ID is much better than my non-native plant ID. Therefore, if you think I’ve made a mistake, please leave a comment below. I’d love to know more!
Non-native / Invasive Species in Hawaiʻi
My list is in alphabetical order by the common names, not the scientific names.
In any case, I’m not going to split hairs regarding whether I label a species non-native or invasive. The reality is that they shouldn’t be in Hawaiʻi, and all non-native plants carry a different weed risk assessment score.
In my experience, these are the ten most invasive plant species in Hawaiʻi, but if you have a different thought, I’d love to more in the comments!
Koa Haole - (Leucaena leucocephala)
Koster’s Curse/ Soapbush - (Miconia crenata)
Strawberry Guava - (Psidium cattleyanum)
Octopus Trees - (Heptapleurum actinophyllum)
Shoebutton (Ardisia elliptica)
Juniper Berry - (Citharexylum caudatum)
Brazilian Pepper/ Christmasberry Tree - (Schinus terebinthifolia)
Guinea Grass (Megathyrsus maximus)
Fountain Grass (Cenchrus setaceus)
Palmgrass (Setaria palmifolia)
Acacia Petit Feuille / False Koa
(Acacia confusa) [Invasive] - A. confusa can easily be confused for one of Hawaiʻi’s two native Koa species.
I took this photo on the Wiliwilinui Ridge Trail.
African Tulip Tree
(Spathodea campanulata) [Invasive] - Generally speaking, an African Tulip Tree is most notable from afar when its orange flowers are blooming.
By this, I mean that when on many hikes, such as Waʻahila Ridge, you can look down into Mānoa or Pālolo Valleys and spot one of these trees from some distance away.
Allspice
(Pimenta dioica) [Invasive] - Pimenta dioica reminds me of one of Hawaiʻi’s native Gardenia species.
Angel’s Trumpet
(Brugmansia sp.) [Invasive]
Arrowleaf Sida
(Sida rhombifolia) [Invasive] - Sida rhombifolia may be confused with the native ʻIlima of the same genus, but if you look closely at the flowers and leaves, there are some notable differences to pick out, including color and shape.
Asian Butterfly Bush
(Buddleja asiatica) [Invasive] - I took this photo on the Mt. Kaʻala Trail.
Asparagus-fern / Sprenger's asparagus
(Asparagus aethiopicus) [Invasive] - I took this photo on the Waʻahila Ridge Trail.
Australian Daisy
(Erigeron karvinskianus) [Invasive] - I took this photo on the KST just before Pyramid Rock.
Autograph Tree
(Clusia rosea) [Invasive] - Autograph trees are popular in landscaping settings, but they have spread beyond the confines of people’s homes to native mountainous areas.
I took this photo on the Mauʻumae Ridge Trail (Puʻu Lanipō).
Bamboo Orchid
(Arundina graminifolia) [Invasive] - Hawaiʻi has three native orchid species, but we also have a number of invasive ones that are much more common to see, such as the Bamboo Orchid.
I took this photo on the Mānana Ridge Trail.
Beggarticks / Shepherd’s Needles
(Bidens alba) [Invasive] - Hawaiʻi is home to a number of native Bidens species across the islands, but Bidens alba is not among them.
This was taken on the Mokulēʻia Access Road.
Begonia valida
[Invasive] - Hawaiʻi does have one Begoniaceae species, but this is not it.
That being said, I unfortunately found this one growing in a highly native/ pristine forest on Oʻahu.
Bellyache Bush
(Jatropha gossypiifolia) [Invasive] - Bellyache is one of Hawaiʻi’s faster spreading dry forest invasive species.
This photo was taken in at Diamond Head, but it is also very common to see along the Kaiwi Shoreline and the Makapuʻu Lighthouse Trail.
Billygoat Weed / Cứt lợn due
(Ageratum conyzoides) [Invasive] - I took this photo on the Mokulēʻia Trail.
Black Wattle Trees
(Acacia mearnsii) [Invasive] - Black Wattle trees are endemic in their home range in Australia, but they were a purposeful introduction in Hawaiʻi, where they are now invasive.
I took these photos on the Kuaokalā Trail.
Brazilian Begonia
(Begonia hirtella) [Invasive] - I took these photos on the Luaʻalaea Falls Trail, but Begonia hirtella can also be seen all over the Tantalus Loop.
Brazilian Pepper / Christmasberry Tree
(Schinus terebinthifolia) [Invasive] - Schinus terebinthifolia is found in many dry and mesic forests across Hawaiʻi.
It grows thick like Koa Haole, and it can easily take resources away from native plants because of how dense, tall, and thick it grows.
I took these photos on the ʻAiea Loop Trail, and the Hanauma Bay Rock Bridge Trail.
Bristleleaf / Lemon Drop
(Thymophylla tenuiloba) [Invasive] - This species is native to Texas and Mexico, but it can be found around coastal areas in Hawaiʻi.
I took this photo on the Kaiwi Coast.
Bristletips
(Oxyspora paniculata) [Invasive] - I took this photo on the Puʻu Kōnāhuanui Ridge Trail.
Cape Ivy
(Delairea odorata) [Invasive] - D. odorata can commonly get confused with one of Hawaiʻi’s many native Sicyos species, especially when their ranges overlap.
This is the case where this was taken on the Puʻu Huluhulu Trail.
Cathedral Bells
(Kalanchoe pinnata) [Invasive]
Common Lantana
(Lantana camara) [Invasive] - Lantana camara is a widespread weed across many elevations, from coastal areas to high wet mountainous environments.
I took these photos on the Hanauma Bay Rim and Kaipapaʻu Pillbox Trail.
Common Purslane
(Portulaca oleracea) [Invasive] - Portulaca oleracea can be easily confused with the native ʻIhi (Portulaca lutea), but there are a few very minor differences that can be difficult to describe.
I took these photos on the Hanauma Bay Rim Trail.
Cook Pine
(Araucaria columnaris) [Non-native] - Cook Pines are a non-native introduction in Hawaiʻi, as their native home range is New Caledonia.
However, Cook Pines were used in past reforestation efforts, which is why they can be found across environments in Hawaiʻi today, from a little above sea level to a few thousand feet.
I took these photo on the Mokulēʻia Access Road at about 1,500 ft. (457 m) in elevation.
Coral Vine
(Antigonon leptopus) [Invasive] - I took these photos on the Kaiwi Coastline Trail.
Coralberry
(Ardisia crenata) [Invasive] - I took this photo on the Waʻahila Ridge Trail.
Corkystem Passionflower
(Passiflora suberosa) [Invasive]
Crofton Weed / Mexican Devil
(Ageratina adenophora) [Invasive]
Delta Maidenhair Fern
(Adiantum raddianum) [Invasive] - I took this photo in a stream in the back of Moanalua Valley.
Eriocapitella sp.
(Eriocapitella sp.) [Invasive] - This was taken in Hawaiʻi Volcanoes National Park on the Kīlauea Iki Trail.
European Strawberry
(Fragaria vesca) [Invasive] - Hawaiʻi does have a native Strawberry, but this is not it.
I took this on the Halemaʻumaʻu Trail.
False Meadowbeauty
(Pterolepis glomerata) [Invasive] - False meadowbeauty is an invasive species in Hawaiʻi that can be found lining Koʻolau trails in any area with an abundance of rainfall.
Thankfully, False Meadowbeauty doesn’t seem to outcompete Uluhe, which is why I have only ever noticed it lining trails where humans have created an opening, rather than growing elsewhere among the other native plants.
This photo was taken on the Papali Ridge Trail.
Florida Blackberry
(Rubus argutus) [Invasive]
Fire Tree
(Morella faya) [Invasive] - I took this photo on a remote section of the Waʻianae Summit Trail (WST).
However, Morella faya can more easily be seen along the Crater Rim Trail, which is where the second photo is from.
Fountain Grass
(Cenchrus setaceus) [Invasive] - All of the grass that you can see lining the Diamond Head Trail is invasive Fountain Grass.
Gaïacwood
(Guaiacum officinale) [Invasive] - I took this photo on the Lanikai Pillbox Trail (Kaʻiwa Ridge).
Glory Bower
(Clerodendrum chinense) [Invasive] - I took this photo in Punaluʻu Valley.
Golden Crown-beard
(Verbesina encelioides) [Invasive] - I took these photos on the Hanauma Bay Rim Trail.
Gorse
(Ulex europaeus) [Invasive] - Gorse is one of Hawaiʻi’s nastiest introduced weeds.
It forms a thick blanket where it grows in high-altitude pastures/ shrublands, essentially choking out anything native that might have a chance to grow. However, I have noticed little micro-climates beneath the gorse, where native plants have found a way to survive in the shaded environment.
These photos were taken on Mauna Kea.
Guava
(Psidium guajava) [Invasive] - I took this photo on Puʻu ʻO Kona.
Guinea Grass
(Panicum maximum) [Invasive] - Guinea grass is extremely widespread across the islands, and it grows extremely well in the same conditions as Koa Haole, making it one of the most invasive plants that Hawaiʻi is forced to combat today.
I took these photos on the Keālia Trail.
Hairy Abutilon
(Abutilon grandifolium) [Invasive] - Hawaiʻi does have four native Abutilon species, but this one is not one of them.
I found this one at a random location in the Waiʻanaes.
High Ridge Moho
(Heliocarpus americanus) [Invasive] - Like many invasive species, High Ridge Moho was introduced intentionally for reforestation purposes, and then subsequently, it began spreading as an invasive species.
I took this photo on the Puʻu Manamana Trail.
Hummingbird Fuchsia
(Fuchsia magellanica) [Invasive] - F. magellanica is native to South America, but this was taken in Hawaiʻi Volcanoes National Park.
Indian Fleabane
(Pluchea indica) [Invasive] - I took this photo on the North Shore Kaʻena Point Trail.
Indonesian Cinnamon / Cinnamon Tree
(Cinnamomum burmannii) [Invasive] - The Cinnamon tree is an invasive tree that I typically find growing in mesic to wet forests in Hawaiʻi.
That being said, it can be found on ridges and valleys across Oʻahu, where I took this photo in Nuʻuanu Valley on the Lulumahu Falls Trail.
Ironwood / Coastal She-oak
(Casuarina equisetifolia) [Invasive] - Love them or hate them, Ironwoods are invasive in Hawaiʻi.
Be that as it may, C. equisetifolia is extremely common to find growing around coastal areas, but many have migrated to upper-elevation areas too.
Furthermore, Ironwoods were purposely introduced in the 1800s, and since then, they have spread across the islands because they seed very aggressively.
These photos were taken on the Kuaokalā Trail.
Ivy-leaved Morning Glory
(Ipomoea cairica) [Invasive] - Ipomoea cairica can be found growing in the same habitat as native Ipomoea species, such as Pōhuehue, as was the case where I took this photo on the Kaiwi Coast.
Java Plum
(Syzygium cumini) [Invasive] - Java Plum is a highly invasive tree found on trails all over Oʻahu, especially west Oʻahu on trails from Keālia to Peacock Flats.
That being said, I took these photos on the Pride Rock Trail and Keālia.
Juniper Berry
(Citharexylum caudatum) [Invasive] - Juniper berry is incredibly widespread in mountainous areas across Hawaiʻi.
Furthermore, Waʻahila Ridge is covered in Juniper berry, but these photos were taken on the ʻIliahi Ridge Trail.
Kiawe
(Prosopis pallida) [Invasive] - Don’t let the Hawaiian name fool you. Kiawe is not a native Hawaiian tree, but rather, it’s highly invasive.
In any case, you’re probably familiar with the tree if you’ve ever stepped on one of their thorns because they can easily go through a pair of shoes!
I took these photos on the Kaiwi Shoreline Trail.
King Fern
(Angiopteris evecta) [Invasive] - Angiopteris evecta is a highly invasive fern that can cover large areas in Hawaiʻi and consume a lot of resources away from native plants.
I took this photo on the summit of Puʻu Lanihuli.
Koa Haole
(Leucaena leucocephala) [Invasive] - Depending on who you ask, they may say that Koa Haole is the most invasive plant in Hawaiʻi.
In any case, Leucaena leucocephala can be found growing thick across thousands of acres of low-lying dry forest, especially if an area or a lot has gone neglected.
Typically, there isn’t a side of any island where you can drive and not see it. However, it’s only once you start gaining elevation that Koa Haole thins and eventually stops.
These photos were taken right off of the Mt. Kaʻala Trail.
Koster’s Curse / Soapbush
(Miconia crenata) [Invasive] - Anywhere and everywhere in wet Hawaiian forests, one can find Koster’s Curse, as it is one of the most established invasive plants in Hawaiʻi today.
I took this photo on the ridge leading up to Puʻu Ōhulehule.
Lauaʻe Fern
(Microsorum scolopendria) [Invasive] - Just like Kiawe, don’t let the Hawaiian name fool you. The Lauaʻe fern is not a native Hawaiian species.
I took this photo in the Waiʻanae Mountains.
Logwood
(Haematoxylum campechianum) [Invasive] - I took this photo on the lower elevations of the Kuliʻouʻou Ridge Trail.
Mangrove
(Rhizophora mucronata) [Invasive] - There’s a long history of mangroves in Hawaiʻi.
However, long story short, they are being removed through conservation efforts today in order to bring back nearshore environments to their once-pristine state.
I took these photos on the Kaiwi Coastline.
Mānuka / Witches Broom
(Leptospermum scoparium) [Invasive] - Despite the Hawaiian sounding name, Mānuka is not a native species, but rather, an invasive introduction.
I took this photo on the Waimano Ridge Trail.
Meadow Ricegrass
(Ehrharta stipoides) [Invasive]
Mickey Mouse Plant
(Ochna serrulata) [Invasive] - Although being a common house/ landscaping species, Ochna serrulata has invaded many Hawaiian forests.
I took this photo on the Puʻu Manamana Trail.
Miniature Sugar Palm
(Arenga caudata) [Introduced]
Morning Glory
(Ipomoea cairica) [Non-native / Invasive] - Ipomoea cairica is not one of the native Ipomoea species, like Pōhuehue.
I took these photos on the North Shore of Oʻahu.
Mueller’s Saltbush
(Atriplex muelleri) [Invasive] - Muller’s Saltbush is an invasive dry coastal species that takes away resources from natives like Pōhuehue, Naupaka, and ʻIlima, to name a few.
I took this photo on the Kaʻena Point Trail.
Nettleleaf Velvetberry
(Stachytarpheta urticifolia) [Invasive] - I took these photos in the Waiʻanae Mountains.
Octopus / Umbrella Tree
(Heptapleurum actinophyllum) [Invasive] - Octopus trees are incredibly invasive.
If you’ve ever looked up at the ridges when driving around Kahana Bay or on the windward side of the H-3 Freeway, you are looking at entirely invasive forests filled with Octopus trees.
In some places, they will grow as high as the Koʻolau Summit, and many people have unfortunately used them for landscaping purposes.
One easy trail to see them is the Crouching Lion Trail.
Orchid Tree
(Bauhinia purpureai) [Non-native] - B. purpurea is a common non-native ornamental in Hawaiʻi, and it can frequently be seen growing in landscaped areas, such as the University of Hawaiʻi at Mānoa or similar places.
Oriental False Hawksbeard
(Youngia japonica) [Invasive] - I took this photo in Kaluanui.
Palmgrass
(Setaria palmifolia) [Invasive] - Setaria palmifolia is a highly invasive grass that covers mountainous areas where Uluhe does not dominate.
I took this picture on the KST above Kaʻau Crater.
Paper Bark Tree
(Melaleuca quinquenervia) [Invasive] - I took these photos on Lulumahu Ridge, but they can also commonly be seen across central Oʻahu, such as the ʻAiea Loop Trail and Mānana Ridge.
Para Grass
(Brachiaria mutica) [Invasive] - Para grass is the hairy-like grass found commonly in the Waiʻanae Mountains.
I took this photo on the Mokulēʻia Trail.
Parasol Leaf Tree
(Macaranga tanarius) [Invasive] - I took this photo on the Maʻakua Ridge Trail.
Pear Cactus
(Opuntia megapotamica) [Invasive] - Common places to see Opuntia megapotamica on Oʻahu are the ridges in the Waiʻanae Mountains, and in the Koko Crater Botanical Garden.
Philippine Ground Orchid
(Spathoglottis plicata) [Invasive] - Much like the Bamboo Orchid above, the Philippine ground orchid can be just as common in mountainous areas.
I took this photo on the KST above Kaʻau Crater.
Pickerel Weed
(Pontederia cordata) [Non-native / Invasive] - I found this growing in the Waimea Stream on the North Shore of Oʻahu.
Pickleweed
(Batis maritima) [Invasive] - Pickleweed can be found growing in low-lying coastal areas where similar-looking native plants like ʻĀkulikuli grow.
Pigeonberry / Coralberry
(Rivina humilis) [Invasive] - I took this photo on the Keālia Trail.
Pink Fringe
(Arthrostemma ciliatum) [Invasive] - Pink Fringe is a weedy species native to the tropical Americas.
Pink-headed Persicaria
(Persicaria capitata) [Invasive]
Quinine Tree
(Rauvolfia caffra) [Invasive] - I typically find the Quinine Tree at mid-elevations on Oʻahu.
I took this photo on Waʻahila Ridge.
Rainbow Eucalyptus
(Eucalyptus deglupta) [Introduced] - While Rainbow Eucalyptus trees may feel like a Hawaiian staple, they are actually native to areas across Southeast Asia.
Red-leaf Fig
(Ficus congesta) [Introduced]
Ribwort Plantain
(Plantago lanceolata) [Non-native/Invasive] - There are native Plantago species in Hawaiʻi, but P. lanceolata is just a common weed from Europe and Asia.
Sandalwood
[Invasive] - Hawaiʻi has a number of native sandalwood species known locally as ʻIliahi, but this is not one of them.
If you know the exact species, please leave a comment below!
Scrambled Egg Bush
(Senna surattensis) [Invasive] - S. surattensis may be most commonly confused with the endemic Māmane tree because of its brightly colored yellow flowers, but it is more closely related to Kolomona, which is also another common name for this species.
Shakeshake / Fuzzy Rattle Pod
(Crotalaria incana) [Invasive] - I took this photo in the Waiʻanae Mountains.
Shoebutton / Coralberry
(Ardisia elliptica) [Invasive] - Where Shoebutton is found, it generally grows thick.
It’s a blanket across the lower elevations of Kahana Valley (Nākoa Trail), it can be found all the way up to the summit on Kuliʻouʻou, and it will grow from mesic to high rainfall areas across Hawaiʻi, meaning it has a large habitat in Hawaiʻi to thrive.
I took these photos on the ʻAiea Loop Trail.
Silk Oak
(Grevillea robusta) [Invasive] - Silk Oak was a purposeful introduction for reforestation efforts of the past, but today, it is has become an invasive species in Hawaiʻi.
Silky Jackbean
(Canavalia sericea) [Invasive] - Silky Jackbean is an invasive coastal species that takes native habitat away from plants, like Pōhuehue and Maiapilo.
I took this photo on Lanikai Beach.
Silver Buttonwood
(Conocarpus erectus var. sericeus) [Invasive] - C. erectus var. sericeus is a common landscaping tree in Hawaiʻi, but it has unfortunately spread beyond its original intent into native habitats, like where I found this one on the Kaiwi Coast.
Slash Pine
(Pinus elliottii) [Invasive] - I took these photos on the Kuaokalā Trail.
Split Leaf Climber
(Philodendron radiatum) [Invasive] - I took this photo on the ʻAihualama Trail.
Strawberry Guava
(Psidium cattleyanum) [Invasive] - It almost seems like you can’t hike any trail without hiking through Strawberry Guava, as it’s easily one of the most invasive plants in Hawaiʻi.
These photos were taken on the Moanalua Middle Ridge, but even lower-elevation trails, such as the Puna Trail, are covered in Strawberry Guava at near sea level.
Sugi Pine / Japanese Red-Cedar
(Cryptomeria japonica) [Non-native] - Sugi Pines in Hawaiʻi are a non-native introduction, which has since shifted to reforestation efforts today to combat Gorse on Mauna Kea.
On Oʻahu, I only know of two Sugi Pine forests, which are near Kīpapa Summit and Puʻu Kōnāhuanui.
Thimbleberry
(Rubus rosifolius) [Invasive] - Hawaiʻi has two native Rubus species, but Rubus rosifolius is not among them.
I took these photos on Papali Ridge, and the Puʻu Manamana Trail.
Toiletbrush / Himalayan / Kahili Ginger
(Hedychium gardnerianum) [Invasive] - Cultivators will try and market this ginger as a native Hawaiian plant because it has been given a Hawaiian name, but in reality, it’s a highly invasive weed that’s spreading across our native wet forest habitats.
I took this photo on the Tantalus Loop Trail, but they can also be seen across places like Hawaiʻi Volcanoes National Park.
Trumpet Tree
(Cecropia obtusifolia) [Invasive] - Cecropia obtusifolia is not the most common invasive species in Hawaiʻi, but where the tree does grow, it can become a large overstory tree, taking away resources from other native species.
I took this photo on the Mauʻumae Ridge Trail.
Wedelia
(Sphagneticola trilobata) [Invasive] - I took this photo on the Pride Rock Trail.
Zulu Giant
(Stapelia gigantea) [Invasive] - I took this photo on the Hanauma Bay Rim Trail.
Other Plants
While the list above isn’t perfect, meaning some plants could be listed down here as a non-invasive introduction, these are plants that grow in Hawaiʻi that are neither native nor invasive.
Bactris obovata
(Bactris obovata) [Introduced]
Cockspur Coral Tree
(Erythrina crista-galli)
Kava
(Piper methysticum) - Kava is all about the root for its properties as a sedative.
I took this photo on the Maunawili Falls Trail.
Kīpukai
(Heliotropium foertherianum) [Non-native/ Introduced] - Can you see the endemic Hylaeus bees?
Yes, they are pollinating a non-native plant, but the Kīpukai tree has, in a way, been accepted as a native coastal tree even though it’s not. It can be found in many other areas around the Pacific, but not natively in Hawaiʻi.
I took this photo on the Kaiwi Coast.
Paperflower / The Lesser Bougainvillea
(Bougainvillea glabra) [Non-native/ Introduced] - Bougainvillea glabra is a common landscaping tree that can be seen cultivated around Hawaiʻi.
I took these photos in the Koko Crater Botanical Garden.
Plumeria
(Plumeria rubra / P. obtusa) [Non-native/ Introduced] - Plumeria is commonly associated with Hawaiʻi because it is common to see planted as an ornamental around the islands, but Plumeria is not a native Hawaiian plant.
There are a few species here and many more hybrids, so I decided to group them all here.
I took these photos in the Koko Crater Botanical Garden.
Pua Keni Keni
(Fagraea berteroana) - F. berteroana is a non-native Hawaiian import.
I took these photos in the Diamond Head Crater, and the ʻAihualama Falls Trail.
Rose of Venezuela
(Brownea macrophylla) [Introduced]
Sea Grapes
(Coccoloba uvifera) [Non-native/ Introduced] - Sea Grape Trees are a very common coastal species that has been naturalized in Hawaiʻi.
This photo was taken outside of the Kāhala Hotel, but Sea Grapes can be found across many shorelines in Hawaiʻi.
Soursop
(Annona muricata) [Non-native/ Introduced] - Soursop is a popular non-native edible Hawaiʻi introduction.
Natively it can be found in Central America and the Caribbean.
Star Fruit
(Averrhoa carambola) [Non-native/ Introduced] - Star Fruit is often a cultivated tree that originates in Southeast Asia but is grown in Hawaiʻi.
