Osage Orange
Maclura pomifera
The Osage orange (Maclura pomifera) is a resilient, thorny tree famous for its heavy rot-resistant …
Humbert's Maclura (Maclura humbertii)
Madagascar mulberry
Silhouette: T. Michael Keesey
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Maclura humbertii: Madagascar's Hidden Mulberry Relative
Rising from the jagged limestone tsingy formations of Madagascar, a remarkable member of the mulberry family stands resilient against the scorching sun and seasonal droughts. This tree, scientifically known as Maclura humbertii, has long intrigued botanists with its complex history and adaptability to extreme environments.
Beneath its rugged, grey bark flows a thick white latex, a characteristic hallmark of the Moraceae family that serves as a natural defense mechanism. The fibrous inner bark of Maclura humbertii has historically provided local communities with strong cordage and traditional materials.
Although rarely cultivated outside its native range, the species remains an essential ecological component of the Western Indian Ocean's dry deciduous forests. Understanding the biology of Maclura humbertii offers key insights into the evolutionary diversity of tropical woody plants.
Taxonomy
- ∟ царство Plantae
- ∟ division Tracheophytes (Vascular Plants)
- ∟ subdivision Spermatophytes (Seed plants)
- ∟ Angiosperms
- ∟ mesangiosperms (Core angiosperms)
- ∟ eudicots
- ∟ Superrosids
- ∟ rosids
- ∟ order Rosales
- ∟ family Moraceae
- ∟ genus Maclura (Osage orange)
- ∟ species Maclura humbertii (Humbert's Maclura)
Morphology
Maclura humbertii is a deciduous tree or large shrub that can reach heights of up to 15 to 20 meters in favorable forest conditions. The plant features a well-developed branching system, often armed with axillary spines on younger branches, which help protect the foliage from herbivores.
The leaves of Maclura humbertii are arranged alternately along the stems.
- Leaf Blades: The leaves are typically ovate to elliptic, measuring 5 to 12 centimeters in length, with a smooth, glossy upper surface and a slightly paler underside.
- Venation: Pinnate venation is prominent, with lateral veins curving upward near the leaf margins.
- Petiole and Stipules: The petioles are short, ranging from 1 to 2 centimeters, accompanied by small, deciduous stipules.
This dioecious species produces unisexual flowers on separate male and female plants, ensuring cross-pollination.
- Male Inflorescences: The staminate flowers are arranged in elongated, yellowish catkins or spikes, releasing abundant wind-borne pollen.
- Female Inflorescences: The pistillate flowers form dense, globose heads that expand significantly after fertilization.
- Fruits: The resulting multiple fruit (syncarp) is fleshy and globose, comprised of numerous small drupes embedded in a succulent perianth, turning yellowish-green at maturity.
Applications
In the rural regions of Madagascar and the Comoros, the primary value of Maclura humbertii lies in its highly fibrous bark. The inner bark (bast) is harvested to extract strong, durable fibers, which are traditionally woven into ropes, utility sacks, and coarse textiles.
The dense and heavy wood of the tree serves local communities in structural construction and carpentry.
- Construction: The timber is resistant to decay, making it suitable for fence posts, support beams, and tool handles.
- Fuelwood: Due to its high density, the wood is also harvested for charcoal production, though this practice poses ecological concerns.
- Medicinal Latex: The sticky white latex secreted by the leaves and bark is applied topically in traditional medicine to soothe minor skin irritations and promote wound healing.
Interesting facts
The taxonomic journey of Maclura humbertii is a testament to the challenges of botanical classification, as it has been transferred among several genera over the past century. First described in other genera like Chlorophora, it was later classified under Maclura by Corner, and is closely associated with Allaeanthus greveanus and Broussonetia greveana.
In addition to its taxonomic intrigue, the tree plays a crucial role in supporting local wildlife.
- Wildlife Sanctuary: The fleshy multiple fruits are a vital food source for endemic Malagasy animals, including various lemur species and fruit bats, which act as primary seed dispersers.
- Extreme Adaptability: The ability of Maclura humbertii to grow directly out of cracks in limestone karsts highlights its extreme drought tolerance and specialized root system.
Geography of distribution
- Madagascar
- Comoros
- Mayotte
Sources
- Plants of the World Online (POWO), Royal Botanic Gardens, Kew
- World Flora Online (WFO) Taxonomic Consortium
- Tropicos Database, Missouri Botanical Garden
- Global Biodiversity Information Facility (GBIF) Registry
- Muséum national d'Histoire naturelle (MNHN), Paris - Botanical Collection
See also
Silkworm thorn
Maclura tricuspidata
A deciduous tree native to East Asia, Maclura tricuspidata is known for its sweet, melon-flavored …
Dyer's mulberry tree
Maclura tinctoria
A medium to large neotropical tree famed for producing fustic, a natural yellow dye historically …
African Osage Orange
Maclura africana
A woody, thorny scrambler native to southeastern Africa and Madagascar, producing small yellow-orange fruits and …