''Hypocalymma cordifolium'' is a species of flowering plant in the myrtle family

Myrtaceae Myrtaceae (), the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All ...

, and 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 the

south west Southwest is a compass point. Southwest, south-west, south west, southwestern or south-western or south western may also refer to: * Southwest (direction), an intercardinal direction Geography *South West Queensland, Australia *South West (Weste ...

of Western Australia. It is usually an low-growing shrub, but is sometimes erect, with winged stems, heart-shaped leaves arranged in opposite pairs, white or pale pink flowers mostly arranged in pairs in leaf axils, and fruit containing pearly white or pale brown seeds.

Description

''Hypocalymma cordifolium '' is usually a low-growing shrub that typically grows to a height of up to , but is sometimes an erect shrub up to high. Its young stems are prominently winged and sometimes deep red. Its leaves are heart-shaped, long, wide and

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

or on a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

up to about long. The flowers are arranged in up to 16 leaf axils near the ends of branchlets, usually in groups of 2, sometimes singly or in groups of up to 4, on peduncles up to long. There are green or red-tinged

bracteole In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also look ...

s long at the base of the flowers. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s are broadly oblong to egg-shaped, long and wide and green or red-tinged. The petals are white or pale pink, long and there are 25 to 45 stamens with the filaments joined at the base. Flowering occurs all year with a peak between September and November and the fruit is a capsule long containing pearly white or pale brown sees long.

Taxonomy

''Hypocalymma cordifolium'' was first formally described in 1844 by

Johannes Conrad Schauer Johannes Conrad Schauer (16 February 1813 – 24 October 1848) was a botanist interested in spermatophytes. He was born in Frankfurt am Main and attended the gymnasium of Mainz from 1825 to 1837. For the next three years he worked at the Hofgar ...

from an unpublished manuscript by

Johann Georg Christian Lehmann Johann Georg Christian Lehmann (25 February 1792 – 12 February 1860) was a German botanist. Born at Haselau, near Uetersen, Holstein, Lehmann studied medicine in Copenhagen and Göttingen, obtained a doctorate in medicine in 1813 and a do ...

in Lehmann's ''

Plantae Preissianae ''Plantae preissianae sive enumeratio plantarum quas in australasia occidentali et meridionali-occidentali annis 1838-1841 collegit Ludovicus Preiss'', more commonly known as ''Plantae preissianae'', is a book written by Johann Georg Christian Le ...

''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

(''cordifolium'') means 'heart-leaved'.

Distribution and habitat

This species of ''Hypocalymma'' is found in seasonally wet areas, along creek beds or swamps between Jarrahdale and

Margaret River The Margaret River is a river in southwest Australia, southwest Western Australia. In a small catchment, it is the eponym of the town and tourist region of Margaret River, Western Australia, Margaret River. The river arises from a catchment ...

and east along the south coast to

Cape Riche Cape Riche is a cape in the Great Southern region of Western Australia. By road, it is south-east of Perth and north-east of Albany. It is part of the locality of Wellstead and is south of the townsite. Facilities in the area include a bo ...

References

{{Taxonbar, from=Q15367886 cordifolium Endemic flora of Western Australia Rosids of Western Australia Plants described in 1844 Taxa named by Carl Meissner