Editing Elaeocarpus angustifolius

{| class="wikitable" style="float: right; width: 320px; margin-left: 1.25em; margin-bottom: 1em;"
|-
! colspan="2" style="background: #e8e8e8;" | Blue quandong (''Elaeocarpus angustifolius'')
|-
! Scientific name
| ''Elaeocarpus angustifolius'' <sup id="cite_ref-1">[[#cite_note-1|[1]]]</sup>
|-
! Common names
| Blue quandong; Blue Marble Tree <sup id="cite_ref-2">[[#cite_note-2|[2]]]</sup>
|-
! Genus
| [[Elaeocarpus]]
|-
! Family
| [[Elaeocarpaceae]]
|-
! Order
| [[Oxalidales]]
|-
! Growth habit
| Evergreen tree
|-
! Mature height
| Up to 35 m <sup id="cite_ref-3">[[#cite_note-3|[3]]]</sup>
|-
! Native climate
| Wet tropical <sup>[[#cite_note-3|[3]]]</sup>
|-
! Fruit
| Bright blue, roughly spherical drupe, about 15–23 mm across <sup id="cite_ref-4">[[#cite_note-4|[4]]]</sup>
|-
| colspan="2" style="text-align: center;" | [[File:Blaue Früchte (30687165914).jpg|300px|Blue fruits of Elaeocarpus angustifolius]]
|}

'''''Elaeocarpus angustifolius''''' is an evergreen rainforest tree known as Blue quandong or Blue Marble Tree. Its native range extends from China through Malesia to Australia and the south-west Pacific, in wet tropical settings that include rainforest and secondary forest. <sup>[[#cite_note-3|[3]]]</sup><sup id="cite_ref-5">[[#cite_note-5|[5]]]</sup>

== Description ==

The tree can become large and may develop buttress roots. It is associated with rainforest and secondary-forest habitats and remains evergreen in warm, moist climates. <sup>[[#cite_note-3|[3]]]</sup><sup>[[#cite_note-4|[4]]]</sup> Its eventual size and root development make long-term container culture a staging or training option rather than a natural endpoint.

The fruit is a bright blue, approximately spherical drupe about 15–23 mm across. The blue surface colour is a structural effect rather than ordinary blue flesh, and fruit and stone characters vary among regional material. <sup>[[#cite_note-4|[4]]]</sup><sup>[[#cite_note-5|[5]]]</sup>

== Cultivation ==

=== Soil and water ===

In its native rainforest and secondary-forest setting, ''Elaeocarpus angustifolius'' grows where warmth and moisture are reliable. Use fertile, humus-rich soil that retains moisture but drains freely; a slightly acid root zone around pH 5.5–6.5 is the stated horticultural preference. <sup>[[#cite_note-4|[4]]]</sup> Keep young plants evenly supplied with water during active warm growth, while avoiding stagnant saturation around the roots. A site or container should allow for vigorous root development and rapid drainage rather than a shallow, chronically wet root zone.

=== Sun and humidity ===

Full sun is preferred, although some shade is tolerated. <sup>[[#cite_note-4|[4]]]</sup> Give a young plant bright light with protection from abrupt exposure changes, then increase sun as its root system establishes. Warm, humid air and good airflow fit the wet-tropical habitat better than a cool, stagnant enclosure. <sup>[[#cite_note-3|[3]]]</sup>

=== Seasonal changes ===

The species is evergreen and associated with warm, moist tropical conditions. <sup>[[#cite_note-3|[3]]]</sup> As a genus-level cultivation inference, maintain steady root-zone moisture through warm active growth and reduce irrigation only when cooler or drier weather slows uptake; do not impose a deliberate dry dormancy. Drainage remains important when rain or irrigation is frequent. A fixed flowering calendar and a species-specific cold threshold are not assigned here.

== Propagation ==

Seed is the primary propagation route in the species treatment. The hard, woody seed can germinate slowly and erratically. <sup>[[#cite_note-4|[4]]]</sup> Sow clean seed in a free-draining medium in light shade and keep it evenly moist without waterlogging; avoid treating an individual germination time as a dependable schedule.

The following are genus-level propagation methods rather than species-specific success guarantees: carefully filing the shell or cracking it enough to admit moisture may speed germination, but damage to the embryo can ruin the seed; almost-ripe shoots may be tried in sandy soil. <sup>[[#cite_note-4|[4]]]</sup> Handle seedlings gently during transplanting and move them before a large root system makes disturbance more difficult.

== Flowering, fruiting, and harvest ==

The flowers are described as creamy, and the fruit develops into a vivid blue drupe. <sup>[[#cite_note-4|[4]]]</sup><sup>[[#cite_note-5|[5]]]</sup> Fruit colour and stone form vary among regional material; measurements associated with plants identified as ''Elaeocarpus grandis'' should not be transferred to ''E. angustifolius'' without confirming the identification. <sup>[[#cite_note-5|[5]]]</sup>

Harvest timing is best judged from fully developed fruit colour and local experience with correctly identified trees. A universal bearing age, crop calendar, or yield should not be assumed from a single regional account.

== Fruit and uses ==

Ripe fruit is used as food in parts of the species' range. Such use does not establish a universal preparation or safety rule: use only correctly identified fruit and follow established local culinary practice. <sup>[[#cite_note-4|[4]]]</sup>

The hard stone and vivid blue outer colour are distinctive features, while the edible portion and flavour can vary with provenance and maturity. <sup>[[#cite_note-4|[4]]]</sup><sup>[[#cite_note-5|[5]]]</sup>

== Photos ==

[[File:Blue Marble Closeup - Hoomaluhia Botanical Garden.jpg|260px|Blue Marble Tree fruit at Hoomaluhia Botanical Garden]]

[[File:Starr-090519-8097-Elaeocarpus angustifolius-leaves-Kula-Maui (24837780352).jpg|260px|Leaves of Elaeocarpus angustifolius at Kula, Maui]]

== References ==

* <span id="cite_note-1"></span>[[#cite_ref-1|↑]] '''[1]''' [https://api.gbif.org/v1/species/match?name=Elaeocarpus%20angustifolius GBIF species match: Elaeocarpus angustifolius].

* <span id="cite_note-2"></span>[[#cite_ref-2|↑]] '''[2]''' [https://api.inaturalist.org/v1/taxa?q=Elaeocarpus%20angustifolius iNaturalist taxon API: Elaeocarpus angustifolius].

* <span id="cite_note-3"></span>[[#cite_ref-3|↑]] '''[3]''' [https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:833771-1 Elaeocarpus angustifolius | Plants of the World Online | Kew Science].

* <span id="cite_note-4"></span>[[#cite_ref-4|↑]] '''[4]''' [https://tropical.theferns.info/viewtropical.php?id=Elaeocarpus+angustifolius Elaeocarpus angustifolius - Useful Tropical Plants].

* <span id="cite_note-5"></span>[[#cite_ref-5|↑]] '''[5]''' [https://en.wikipedia.org/wiki/Elaeocarpus_angustifolius Elaeocarpus angustifolius].

== Image credits ==

* ''Blaue Früchte (30687165914).jpg'': photograph by Theo Crazzolara, Wikimedia Commons; CC BY 2.0. [https://commons.wikimedia.org/wiki/File:Blaue_Fr%C3%BCchte_(30687165914).jpg File page].

* ''Blue Marble Closeup - Hoomaluhia Botanical Garden.jpg'': photograph by Daniel Ramirez, Wikimedia Commons; CC BY 2.0. [https://commons.wikimedia.org/wiki/File:Blue_Marble_Closeup_-_Hoomaluhia_Botanical_Garden.jpg File page].

* ''Starr-090519-8097-Elaeocarpus angustifolius-leaves-Kula-Maui (24837780352).jpg'': photograph by Forest and Kim Starr, Wikimedia Commons; CC BY 3.0 US. [https://commons.wikimedia.org/wiki/File:Starr-090519-8097-Elaeocarpus_angustifolius-leaves-Kula-Maui_(24837780352).jpg File page].

[[Category:Elaeocarpus]]
[[Category:Elaeocarpaceae]]
[[Category:Tropical fruit trees]]