What's an invasive plant?

Saguaro flower. Saguaros are native here.

NPS Photo

Native plants evolved as part of the ecosystem and have been part of our landscape since before the arrival of Europeans.They have adapted through natural selection to the soil, climate, and other plants and animals of the ecosystem. A non-native plant species is not native to an area and has usually been introduced by people. Examples of plants not native to Tucson include a rose bush or a boojum tree. The boojum tree is native to parts of the Sonoran Desert, but not the Tucson area.

 

Buffelgrass fire. Buffelgrass is not native here.

NPS Photo

Non-native plants are considered INVASIVE when they are known to displace native plant species. Invasive non-native species can be harmful or destructive to native plant and animal communities, as well as negatively impact local economies and human safety.

The park has many non-native plants that are not invasive. There are also some that are highly invasive, like BUFFELGRASS. Buffelgrass can out-compete native plants and carry fire in an ecosystem which is not fire adapted.

Buffelgrass has the potential to convert large areas of the Sonoran Desert into a buffelgrass grassland, subject to frequent, high-intensity fires. A landscape-level change such as this would eliminate the iconic saguaro, reduce native plants and animals, and endanger human lives and homes.

 

Learn more about our worst invasive plants:

-Buffelgrass (Pennisetum ciliare syn. Cenchrus cilaris)
-Fountain grass (Pennisetum setaceum syn. Cenchrus setaceus)
-African lovegrass (Eragrostis echinochloidea)
-Natal grass (Melinis repens)
-Salt cedar or tamarisk (Tamarix species)
-Malta starthistle (Centaurea melitensis)
-Sahara mustard (Brassica tournefortii)
-Stinknet (Oncosiphon pilulifer)

 

Here's a list of non-native plant species found in the park:

GRASSES

Agrostis stolonifera, creeping bentgrass
Avena fatua, wild oat
Bothriochloa ischaemum, yellow bluestem
Bromus catharticus, rescuegrass
Bromus rubens, red brome
Bromus tectorum, cheatgrass
Cenchrus ciliaris (a.k.a. Pennisetum ciliare), buffelgrass
Cenchrus setaceus (a.k.a. Pennisetum setaceum), fountain grass
Cynodon dactylon, Bermuda grass
Dactyloctenium aegyptium, Egyptian grass
Digitaria ciliaris, southern crabgrass
Digitaria sanguinalis, hairy crabgrass
Echinochloa colona, jungle rice
Enneapogon cenchroides, soft feather pappus grass
Eragrostis cilianensis, stink grass
Eragrostis curvula, weeping lovegrass
Eragrostis echinochloidea, tickgrass
Eragrostis lehmanniana, Lehmann lovegrass
Hordeum murinum ssp.
Glaucum, wild barley
Lamarckia aurea, goldentop grass
Melinis repens, rose Natal grass
Panicum antidotale, blue panicgrass
Phleum pratense, timothy
Poa annua, annual bluegrass
Poa pratensis, Kentucky bluegrass
Polypogon monspeliensis, annual rabbitsfoot grass
Polypogon viridis, beardless rabbitsfoot grass
Schismus arabicus and S. barbatus, Mediterranean grass
Sorghum halepense, Johnson grass
Vulpia myuros, rat-tail fescue

FORBS

Asphodelus fistulosus, onionweed
Brassica tournefortii, Sahara mustard
Capsella bursa-pastoris, shepherd's purse
Centaurea melitensis, Malta star-thistle
Dimorphotheca sinuate, Cape marigold
Erigeron bonariensis, Asthmaweed
Erodium cicutarium, redstem filaree
Herniaria hirsuta var. cinerea, hairy rupturewort
Lactuca serriola, prickly lettuce
Lamium amplexicaule, henbit
Lasiopogon sp., no common name in English, in Afrikaans it is wolbossie - tentative ID on potentially recent introduction
Malva parviflora, cheeseweed
Marrubium vulgare, horehound
Matthiola parviflora, small-flowered stock
Melilotus species, sweetclover
Mentha spicata, spearmint
Mollugo cerviana, threadsteam carpetweed
Oncosiphon pilulifer, stinknet (a.k.a. globe chamomile)
Polygonum aviculare, prostrate knotweed
Rumex acetosella, sheep sorrel
Rumex crispus, curly dock
Salsola tragus, prickly Russian thistle
Sisymbrium irio, London rocket
Sonchus asper, S. oleraceus, sow thistle
Taraxacum species, dandelion
Tragopogon dubius, yellow salsify
Tribulus terrestris, goathead (a.k.a. puncture vine)

SHRUBS & TREES

Leucophyllum frutescens, Texas ranger
Nerium oleander, oleander
Nicotiana glauca, tree tobacco
Parkinsonia aculeata, Mexican palo verde
Prosopis chilensis, Chilean mesquite
Searsia lancea, African sumac
Senna artemisioides, silver senna (a.k.a. feathery cassia)
Tamarix aphylla, athel tamarisk
Tamarix chinensis, five-stamen tamarisk
Ulmus pumila, Siberian elm

CACTI

Opuntia basilaris, beavertail prickly pear
Opuntia engelmannii var. linguiformis, cow's tongue prickly pear