Northern Island Tree Mallow (Lavatera assurgentiflora ssp. assurgentiflora) is a plant native only to the Calfirnia Channel Islands. It occurs on the islands only in a very few tenuous populations consisting of a few individuals each, on San Miguel Island, and, until recently, Anacapa Island. Natural populations of this plant are probably essentially extinct on Anacapa. Fortunately, the Santa Barbara Botanic Garden, which is an active member of the Center for Plant Conservation’s network of rare plant conservators, has maintained collections of the Middle and West Islet genotypes at the Garden.

We were able to obtain propagation material from this stock, and in our nursery produced about 200 seedlings, which we planted on East Islet in March 2000. To protect the islands from introduction of mainland organisms, we take special measures in our nursery to isolate our growing stock from biotic contamination (most of which are common pests in mainland nurseries), monitor for potential pest ‘hitchhikers’, and subject each plant to a rigorous program of inspection and prophylactic ‘de-contamination’ before we transport them to the islands.

The rose mallow seedlings were planted from large containers (tall 2-1/2 gallon pots) each of which contained three well-rooted seedlings. Anacapa’s soils are clay loams, with adequate balanced plant nutrient content, so no soil amendments were needed. These plantings are now well-established, and some are already flowering and fruiting. These will serve as a genetic reservoir for further propagation and plantings on Middle and West Islets.

We provided minimal supplemental watering during this first summer, and that only because last winter’s rains were sparse, and the dry season approaching, by the time we got the plants into the ground. We have applied ¾ to 1 gallon water to each plant monthly. Because the island has no natural water supply, we brought our irrigation supply from the mainland, in barrels.

Island Tree Mallow is a medium to large shrub, with large bright green leaves and large bright-pink flowers. With some supplemental water, it will remain in leaf and flower most of the year, so can be an attractive addition to a landscape. The new plantings on East Islet are 1) around the bulletin board near the Visitor Center, 2) along the south edge of the island (in the vicinity of the large concrete former water-collection pad), and 3) about 50 yards east of the residences.

We have also propagated purple needlegrass (Nasella pulchra) from island material, and have planted to date about 2000 seedlings on East Islet, in areas where native vegetation has been displaced by the expansion of red-flowered iceplant (Malephora crocea). These plantings will serve as seed-producing populations for revegetation of areas newly cleared of iceplant. Some of these seedlings can be observed in the planted areas near the bulletin board.

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