''Ceanothus arboreus'' is a species of

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

to small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...

in the family

Rhamnaceae The Rhamnaceae are a large Family (biology), family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. Rhamnaceae is included in the order Rosales. The family contains about 55 genera and 950 specie ...

, commonly known as the feltleaf ceanothus, island ceanothus, and island mountain lilac.Calflora: ''Ceanothus arboreus''
/ref> It is the largest member of the California lilacs (the ''

Ceanothus ''Ceanothus'' is a genus of about 50–60 species of nitrogen-fixing shrubs and small trees in the buckthorn family (Rhamnaceae). Common names for members of this genus are buckbrush, California lilac, soap bush, or just ceanothus. ''"Ceanothus" ...

'' genus), and is characterized with glossy, dark green foliage that is adorned by pale blue to white flowers in bloom. It is endemic to the

Channel Islands of California The Channel Islands () are an eight-island archipelago located within the Southern California Bight in the Pacific Ocean, off the coast of California. They define the Santa Barbara Channel between the islands and the California mainland. The ...

and

Guadalupe Island Guadalupe Island () is a volcanic island located off the western coast of Mexico's Baja California peninsula and about southwest of the city of Ensenada in the state of Baja California, in the Pacific Ocean. The various volcanoes are extinc ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, only being re-discovered on Guadalupe Island after the elimination of

feral goat The feral goat is the domestic goat (''Capra hircus'') when it has become established in the wild. Feral goats occur in many parts of the world. Species Feral goats consist of many breeds of domestic goats, all of which stem from the wild go ...

Description

''Ceanothus arboreus'' is a spreading bush growing up to in height.Jepson eFlora: ''Ceanothus arboreus''
/ref> It has large, glossy, dark green leaves which are leathery or felt-like on their undersides. Its showy bright blue flowers grow in plentiful

panicle In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...

s, or bunches, of tiny five-lobed blossoms. Some varieties and cultivars have light, powder purple blooms, and others bear darker purple flowers. The bloom period is February to April. The fruits are three-lobed, triangular capsules.

Distribution

The plant is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to three of the

Santa Cruz Island Santa Cruz Island (Spanish language, Spanish: ''Isla Santa Cruz'', Chumashan languages, Chumash: ''Limuw'') is located off the southwestern coast of Ventura, California, United States. It is the largest island in California and largest of the ei ...

, Santa Rosa Island, and Santa Catalina Island, and it is also found on

. It is found on slopes in

coastal sage scrub Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is ...

and

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

habitats.

Cultivation

Ceanothus arboreus'' is cultivated as an

ornamental plant Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...

for use in drought tolerant and

wildlife garden A wildlife garden (or habitat garden or backyard restoration) is an Biophysical environment, environment created with the purpose to serve as a sustainable haven for surrounding wildlife. Wildlife gardens contain a variety of habitats that cater t ...

s and

natural landscaping Natural landscaping, also called native gardening, is the use of native plants including trees, shrubs, groundcover, and grasses which are local to the geographic area of the garden. Benefits Maintenance Natural landscaping is adapted to t ...

projects.Las Pilitas Nursery Horticultural Database: ''Ceanothus arboreus'' (Tree Lilac, Island Mt. Lilac)
/ref> Butterflies like the flowers and the quail eat the seeds.

Cultivars

Numerous

cultivars A cultivar is a kind of cultivated plant that people have selected for desired traits and which retains those traits when propagated. Methods used to propagate cultivars include division, root and stem cuttings, offsets, grafting, tissue cult ...

have been selected for garden use, including: * ''Ceanothus arboreus'' 'Cliff Schmidt' — more compact habit and deeper blue flowers. *''Ceanothus arboreus'' 'Owlswood Blue'. *''Ceanothus arboreus'' 'Powder Blue' — Powder Blue Ceanothus, Compact Feltleaf Ceanothus. *''Ceanothus arboreus'' 'Skylark' *''Ceanothus arboreus'' 'Trewithen Blue' — very dark blue flowered form from the Channel Islands. It has received the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

References

External links