Maclura Nutt.

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

A genus of 11 species, from Asia, Africa, the Neotropics and North America. A single species occurs in New Guinea: Maclura cochinchinensis (Lour.) Corner.

Morphology General Habit

Shrubs, scramblers and climbers, armed with straight or curved spines up to 3 cm long (in New Guinea)

Morphology Leaves Stipules

Stipules often minute, free or fused

Morphology Leaves

Leaves alternate and distichous or spirally arranged, base rounded to cuneate, margin entire (in New Guinea), venation pinnate, tertiary veins reticulate

Morphology Reproductive morphology Inflorescences

Inflorescences in leaf axils or on lateral shoots, solitary or paired, unisexual and plants dioecious, both sexes globose-capitate (in New Guinea), each flower subtended by bracts with embedded yellow glands; male inflorescences perianth 4-merous, free or fused at the base, imbricate in bud; stamens 2–3, straight or inflexed in bud; flowers in female inflorescences fused at the base (in New Guinea), perianth imbricate, enlarging in fruit, ovary free or fused to perianth, style with 1 or 2 branches

Morphology Reproductive morphology Flowers Perianth

Perianth becoming fleshy and expanding, adjacent perianths touching, forming a globose whole, endocarp crustaceous.

Ecology

Maclura is found in New Guinea in lowland rain forest, often on forest edges and by rivers, from sea level up to 1800 m.

Recognition

Maclura can be recognised by the presence of thorns, the entire margin of the leaves, the more or less globose inflorescences without bracts, the male flowers with several stamens, the fused perianth of adjacent female flowers, and the globose, fleshy multiple fruits which are usually orange when ripe.

George R. Proctor (2012). Flora of the Cayman Isands (Second Edition). Royal Botanic Gardens, Kew

Morphology General Habit

Dioecious trees with yellowish latex, often armed with spines; leaves entire or toothed, pinnately veined; stipules small, soon falling

Morphology Reproductive morphology Flowers

Staminate flowers in axillary catkin-like spikes; perianth 4-parted; stamens 4, inflexed in bud; ovary rudimentary

Morphology Reproductive morphology Flowers Gynoecium Pistil

Pistillate flowers in dense axillary heads, mingled with bracts similar to the perianth segments; perianth 4- parted, the oblique ovary included, the style filiform, exserted; ovule laterally attached

Morphology Reproductive morphology Fruits

In fruit, the perianths become somewhat fleshy and are tightly crowded together to form a globose syncarp; achenes compressed, oblique at apex.

Distribution

A genus of perhaps a dozen species, one temperate American, one Mexican, one tropical American, and the rest occurring in Africa and Madagascar.

Moraceae, C.C. Berg (University of Bergen). Flora of Tropical East Africa. 1989

Morphology General Habit

Shrubs, treelets or climbers, dioecious, armed with spines

Morphology Leaves

Leaves in spirals or sometimes subdistichous, pinnately veined; stipules lateral, free or connate spine-forming branchlets

Morphology Reproductive morphology Inflorescences

Inflorescences in the axils of the leaves, globose-capitate, bracteate, with embedded yellow dye-containing glands in tepals and bracts

Morphology Reproductive morphology Flowers Tepal

Tepals 4, partly connate

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 4, inflexed in bud; pistillode present in staminate flower

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary free; stigmas 1 or 2 (but then unequal in length), filiform

Morphology Reproductive morphology Fruits

Fruiting perianth enlarged, fleshy, yellow to orange; fruit free, somewhat drupaceous

Morphology Reproductive morphology Seeds

Seed rather small; cotyledons thin, equal, plicate.