Cupressaceae Actinostrobus arenarius C. A. Gardner
Etymology
Actinostrobus refers to ‘star’ (actino) and ‘cone’ (strobus); indicating its six-scaled cone.
arenarius refers to ‘sand’; indicating it’s habitat.
Colloquial Name
Bruce cypress
Description
These shrubs or small trees grow between 2 and 5 meters tall and have either a short trunk or multiple stems. The bark is smooth but begins to flake early, forming a thin layer that is brownish-grey. The branches are numerous, spreading outward or growing upward, and remain on the plant for a long time. They create a crown that can be either narrow and conical or more irregular in shape. The smaller branches that bear foliage are also numerous and tend to twist or spread in different directions. They are rigid, slender, short but sturdy, and have a slightly angular shape due to their leaf bases. As the leaves fall off, these branches turn grey-brown or grey.
The leaves grow in clusters of three, arranged in an alternating pattern. They extend down along the stem and are only found in their juvenile form on young plants. The leaves are narrow and lance-shaped, measuring between 3 and 5 millimeters long, sometimes up to 9 millimeters, and about 1 to 1.5 millimeters wide. Their tips can be either straight or slightly curled backward, and the underside has a raised central ridge. The edges and ridge are finely toothed, and the leaf ends in a sharp point. The color varies from green to a slightly bluish-green shade. Tiny openings for gas exchange, called stomata, are arranged in two lines on each surface of the leaf.
The pollen cones grow at the tips of the smallest branches. They are yellowish-green when young but turn light brown as they mature. They are small, measuring about 5 to 7 millimeters long and 2 to 2.5 millimeters wide. Each cone consists of 12 to 18 tiny overlapping scales, arranged in groups of three. These scales are ovate with a pointed tip and have a slight ridge on the underside. Each one contains 2 to 4 small sacs that release pollen.
The seed cones also grow at the tips of short, lateral branchlets, which are slightly thickened and have small leaves. They are usually clustered along the branches and stems. When closed, they have a broadly rounded to conical shape, measuring between 12 and 18 millimeters in length and width. Young cones are bluish-green and sometimes have a waxy coating, but they mature to a purplish-brown or grey-brown color. The cone consists of six tightly packed, similarly sized scales arranged in a circular pattern. These are surrounded by 4 to 6 sets of broad, overlapping scale-like leaves, each set arranged in groups of three. The edges of these leaves are finely toothed, and their tips are rounded and slightly pointed. The tips of the bracts remain entirely hidden within the cone scales.
The cone scales are oblong, measuring 10 to 15 millimeters long and 5 to 8 millimeters wide. They are relatively flat and smooth, with a grey-brown color on the outer surface and a purplish-brown inner surface. Near the base, there are lighter-colored seed scars. The central axis of the cone is about 6 millimeters long and 4 millimeters wide, triangular in shape, and brown in color.
Each cone contains between 8 and 12 seeds, though only a few are fertile. About half of the seeds are positioned between the bases of the cone scales. They are irregularly shaped, either triangular or angular, and measure 4 to 5 millimeters in length. With their attached wings, they reach about 10 millimeters in total length. The seeds are yellowish-brown, while the wings are narrow, about 2 to 3 millimeters wide.
Distribution
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Habitat
The natural habitats for Actinostrobus arenarius are mediterranean-type shrublands. It is naturally found at an elevation of at least 300 up to 300 metres. There are no conifers associated with Actinostrobus arenarius that are known of.
USDA Hardiness zone – 10
Actinostrobus arenarius is hardy to USDA Zone 10 (Bannister & Neuner, 2001), meaning its frost tolerance lies somewhere in the range of -1.1C (30F) to 4.4C (40F).
Species Continuity
The population trend for Actinostrobus arenarius is increasing. There are ongoing threats for Actinostrobus arenarius and they are listed as follows:
IUCN Category – LC
According to the IUCN Red List, Actinostrobus arenarius has been assigned the status of LC(Least Concern). This means that according to the Red List criteria, this species is not qualified as threatened.
Superordinate Taxa
The nearest superordinate taxon for Actinostrobus arenarius is Actinostrobus. The coordinate taxa for Actinostrobus arenarius are therefore:
Actinostrobus arenarius is further placed under Cupressoideae. Actinostrobus arenarius is also placed under Cupressaceae.
This map shows botanical records (points) for this taxon. By opening the map’s sidebar (collapsed by default) you can toggle visibility or change the basemap. By clicking on records, you reveal more information.
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