On Floreana, first island to be colonized in 1832, 26% of its flora is introduced. Like Santa Cruz, Floreana Island presents the four zones Vegetation: coastal, arid and humid transition.

WORST INVASIVE PLANTS IN GALAPAGOS* Blackberry (Rubus, 5 varieties) Guava (Psidium guajava) Cascarilla o Quinina (Cinchona pubescens) Cedrela (Cedrela odorata) Supirosa (Lantana camara) Sauco (Cestrum auriculatum) Maracuyá (Passiflo) Pomarosa (Syzygium jambos) Hoja del aire (Bryophyllum pinnatum) Pasto elefante (Pennisetum purpureum) Laurel (Cordia alliodora) Cabuya (Furcraea hexapetala) Sauco macho (Citharexylum gentryi-Verbenaceae) Tulipán africano (Sphatodea campanulata) Zaragoza (Aristolochia odoratisima) Higuerilla (Ricinus communis) Poleo (Hyptis pectinata) Saboya (Panicum maximum) Floripondio (Datura y Brugmansia spp) * Marked in bold, invasive plants of Floreana

It is presumed that the introduction of exotic species, mainly plants, began with the arrival of humans to the Galapagos in the seventeenth century, but the greatest introduction occurred in the early nineteenth century, with human colonization of the Islands.

Introduced plants are one of the greatest dangers to the flora of the Galapagos, as many of them are highly invasive, competing with native and endemic plants for light, water, and nutrition.

It is estimated that there are about 700 introduced plants, 50 of which are highly invasive.

Floreana

Introduced in 1832 as an ornamental plant because of its beautiful flowers, "supirosa" (Lantana camara) now covers 3,000 hectares on the island. The "supirosa", along with the guava (Psidium guajava) (8,000 hectares), and "hoja del aire" or kalanchoe (Bryophyllum pinnatum) are the most invasive plant species on the island. They are harmful to local ecosystems because they compete with endemic plants such as Scalesia pedunculata, and prevent the Galapagos petrels (patapegada), endemic birds of the Galapagos, from reaching their nesting sites.

	NATIVE AND ENDEMIC FLORA OF THE GALAPAGOS » Watch presentation

Romerillo (Macraea laricifolia), besides being a victim of trampling by donkeys and goats, is being displaced by guava and "supirosa", and other introduced plants growing in the dry zone.

Other vulnerable plants on this island are the Galapagos croton, Croton scouleri, Darwiniothamnus spp., the "cafetillo" (Psychotria angustata), the Alternanthera halmifolia, creeping plants such as Lycopodium pinnatifidus, and the smooth-stemmed tournefortia or "palito negro" (Tournefortia psilostachya).

But not all is bad news. Linum cratericola, a species of plant endemic to Floreana Island, was in danger of becoming extinct when a team of Park Rangers and scientists from the Charles Darwin Foundation discovered four adults in 1997, 16 years after the last record of this species.

Control and eradication actions on Floreana

	CONTROL OF INVASIVE PLANTS » Watch presentation

In three specific sites: "Cerro Pajas", "Cerro Alleri", and "El Asilo de la Paz", "supirosa" is controlled with the stamping-splintering technique (see main photo), and with foliage spraying and regrowth. Guava is controlled with the stamping-splintering technique and a technique where the plant is uprooted and a controlled substance is applied to the affected area. Kalanchoe is controlled with foliage application.

For the protection of the only surviving population of Linum cratericola on Earth, protection quadrants were established in 1997 and since then they have been monitored. Currently there are around 40 seedlings, evidence that the species is regenerating. Seedlings were also transferred to the nursery to save this species from extinction.

As for blackberries, preventive control is performed in the higher part of the island, near the agricultural areas to avoid them from getting out of control.

This program has counted on the support of:

The Charles Darwin Foundation for the Galapagos Islands (CDF) is an international nonprofit research organization dedicated to providing scientific research, technical assistance and information in order to ensure the success of conservation in Galapagos.