Syzygium erythrocalyx
| Johnstone River satinash (Syzygium erythrocalyx) | |
|---|---|
| |
| Scientific name | Syzygium erythrocalyx |
| Common names | Johnstone River satinash; Johnstone River apple; red bud satinash; scarlet satinash |
| Family | Myrtaceae |
| Genus | Syzygium |
| Order | Myrtales |
| Habit | Tropical evergreen rainforest tree, described at about 7–8 m in one North Queensland account and up to 8–15 m in an institutional record |
| Native range | North Queensland rainforest, from lowland and upland sites to about 700 m |
| Fruit | Depressed-globular to apple- or pear-shaped, about 50–70 mm across or 4–8 cm long; white, pink or red, with one or several seeds |
Syzygium erythrocalyx, commonly called Johnstone River satinash, is a tropical evergreen tree of North Queensland rainforest. It is recorded from lowland and upland rainforest to about 700 m, with mature descriptions ranging from about 7–8 m to a maximum of 8–15 m depending on the account and setting.[1][2]
Description[edit | edit source]
Flowers and fruit can be borne on the trunk, branches and twigs. The fruit is depressed-globular in the Australian rainforest treatment, while an institutional account describes it as apple- to pear-shaped. Descriptions range from white through pink to bright red, with fruits about 50–70 mm across or 4–8 cm long and 3–7 cm wide; the fruit may contain one seed or several seeds.[2][3]
The flower description is not uniform between the examined accounts: the Australian rainforest treatment describes large yellow flowers in clusters on the smooth, pinkish stem, while the institutional account describes white flowers on branches and trunk.[2][3]
Cultivation[edit | edit source]
Soil and water[edit | edit source]
The species is associated with very high-rainfall rainforest and is described in cultivation accounts as preferring fertile, loamy, well-drained soil that remains moist and humus-rich. Provide regular moisture without allowing the root zone to stay waterlogged; drainage is especially important when using a large container or a sheltered planting site.[3][4]
Sun and humidity[edit | edit source]
Young plants are described as demanding shade, while institutional cultivation guidance places the species in semi-shade. Give a young tree protection from strong wind and hot, drying exposure; increase light only where foliage remains hydrated and the planting medium still drains freely. Its rainforest origin supports a humid, sheltered establishment environment, but no fixed humidity threshold is established.[3][4]
Seasonal changes[edit | edit source]
The native setting is a warm, very wet tropical-rainforest climate rather than a documented cold or leafless rest. During hot active growth, maintain the moist conditions associated with its rainforest habitat. In cooler, cloudy or unusually wet periods, reduce irrigation enough to preserve aeration and drainage, while protecting young plants from drying winds and cold, saturated roots.[3][4]
Propagation[edit | edit source]
Seed propagation is documented. Fresh seed is recommended in the specialist account, which reports germination within a few weeks; the same account warns that seed can be readily infested by insects. Sow promptly in a clean, free-draining medium and inspect stored or newly collected seed before sowing. No quantified germination rate or seed-storage period is established for this species.[3][4]
Flowering, fruiting, and harvest[edit | edit source]
The species has bisexual flowers, and clusters may occur on branches and the trunk. Flower color is described differently in the available botanical and institutional accounts, as noted above. The fruiting habit is conspicuous because fruit can develop directly from trunk bumps as well as on twigs and branches.[2][3]
No species-specific bearing age, flowering calendar or harvest window is assigned here. Fruit size and color vary across the descriptions, so harvest decisions should be based on the individual tree's documented ripe-fruit characteristics rather than a universal date or color threshold.
Fruit and uses[edit | edit source]
The flesh is described as succulent and somewhat acidic. Fruit is recorded as edible and suitable for raw or cooked use; institutional guidance lists jellies, jams and desserts. These records document culinary use but do not establish a universal food-safety or toxicity guarantee.[3][4]
Photos[edit | edit source]
References[edit | edit source]
Image credits[edit | edit source]
- Syzygium-erythrocalyx-SF24239-05.jpg — fruit at Cairns Botanic Gardens; Steve Fitzgerald; CC BY-SA 4.0; file page.
- Syzygium-erythrocalyx-SF24230-03.jpg — flowers on branches at Cairns Botanic Gardens; Steve Fitzgerald; CC BY-SA 4.0; file page.
- Syzygium-erythrocalyx-SF24230-04.jpg — trunk at Cairns Botanic Gardens; Steve Fitzgerald; CC BY-SA 4.0; file page.
