First described in 1930, the miniature orchid Haraella retrocalla (also known as Harealla odorata) is found in Taiwan growing in deciduous forest. This plant has small dark yellow flowers which have a light yellow, hairy lip with mahogany marks, flowers have a pleasant lemony fragrance, which is quite strong for the size of the plant. Each flower measures about 2.5cms across the sepals and the same from the tip of the dorsal sepal to the tip of the lip, leaves are a mid-green and fleshy. The illustrated plant measure 6cms from the base of the stem to the tip of the newest leaf. Pendant inflorescences arise from the leaf axils and there can be many developing at any one time, each inflorescence can have 3 or more flowers, opening sequentially so the plant can be in flower almost year-round.
Haraella retrocalla needs intermediate to warm temperatures with humidity around 70% and low to medium light conditions. It is best grown on a rough textured mount and given sufficient water to keep the mount from drying out, they appreciate a light misting, however, it is quite tolerant of growing conditions that fall a little below this. Plants can be fed with one quarter to one half-strength fertiliser when in their main growth period, although they have no real dormancy period.