Rubus alceifolius Poir.

Global description
 
Rubus alceifolius is a bushy sarmentose species that emits long stems that can reach up to the treetops. The stem is covered with yellow hairs and abundantly provided with curved spines. The leaves are simple, equipped at the base of the wide petiole, very deeply cut stipules. The leaf blade is broad, oval pentagonal, with 5-7 large lobes. The white flowers with 5 rounded petals are clustered at the ends of short branches. The fruits are orange red, formed from a cluster of small fleshy berries.
 
Cotyledons
 
Cotyledons spatulate, 5 mm long and 3 mm wide. The leaf blade is circular, supported by a short petiole. Midrib and the first two main veins are well marked. The faces are sparsely covered with long hairs.
 
First leaves
 
Leaves alternate, simple short-stalked. The leaf blade is broadly oval with coarsely serrated margin trinervate at the base. Both sides are pubescent as well as the petiole and young stem. The first thorns bent backwards, quickly appear along the stem.
 
General habit
 
Sarmentose bush with multiple stems extending from the strain, 3 to 15 m long and more or less branched. In an open environment, the stems grow in drooping arches after a few meters or crawling on the ground. In forest areas, stems rely on tree branches and can climb up to the canopy and then fall to the ground, where they take root again.
 
Underground System
 
Robust branched Taproot.
 
Stem
 
At the base is a rounded strain from which extend numerous sarmentose stems, 3 to 15 m long and a section of 0.4 to 3 cm. The stem is covered with an abundant yellow pubescence formed of a mixture of long and short hairs. The stem is covered with spines bent backward.
 
Leaf
 
Leaves simple, alternate, held by a robust petiole, 3  to 11 cm long, pubescent and equipped with curved spines. At the base of the petiole is two stipules broadly ovate, hairy, long and wide of 1 to 2 cm, very deeply laciniate into filiform filaments and quickly deciduous. The leaf blade is thick, oval orbicular more or less as wide as long (young leaves are more oval); it is 5 to 25 cm in diameter. It is clearly lobed, 5 to 7 rounded lobes, more or less acuminate, separated by wide incisions. The lobes are themselves weakly lobed. The leaf base is deeply cordate, with a basal incision measuring up to 6 cm deep, while the summit is wide cornered. The margin is irregularly and coarsely serrated (4 to 7 teeth / cm). The main venation is formed of 5 palmate ribs extending from the base, protruding to the lower face and bearing small curved spines. The lower face is covered with a yellowish or greyish tomentum formed of fine frizzy bristles on the blade and long straight bristles on the ribs. The upper side is slightly pubescent and bubbled.
 
Inflorescence
 
Flowers grouped in axillary clusters or terminal narrow panicles, cylindrical, up to 20 cm in length.
 
Flower
 
The white flowers are hermaphrodite, 1.5 cm to 2 wide, carried by a long pedicel,  5 to 15 mm, pubescent and having curved prickles. Flower buds are ovoid. The flower is underpinned by an oval bract deeply laciniate. The 5 to 6 sepals are unequal, oval, tomentose, 6 to 10 mm long and 4 to 7 mm wide. The externals are appendiculate, having 2 to 5 long tines of 2 to 4 mm at the top. Petals are in 5 to 6 in numbers, orbicular form, unguiculated at the base and widely rounded at the top, 5 to 10 mm long and 4 to 9 mm wide. They fall quickly. The stamens are very numerous (160 to 230), having a 5 mm long filament topped with anthers of 0.5 to 0.8 mm long. The carpels are numerous (over 150) with glabrous ovary, surmounted by a filiform style, 10 mm long, exceeding the stamens and having at the top a dilated stigma.
 
Fruit
 
The fruit is a polydrupe of globular shape, 12-28 mm in diameter at maturity grouping 7-75 drupels (usually over 30) of bright orange red color and often topped with persistent style or exceeded by the styles of the undeveloped ovaries. Each drupel contains a seed.
 
Seed
 
Seed obovate, asymmetrical, 2 mm long and 1 to 1.5 mm wide. The seed coat is cream colored, heavily wrinkled or crosslinked, especially dorsally.

Origin

Rubus alceifolius is native to Southeast Asia, Indonesia.

Worldwide distribution

Probably introduced first in Madagascar and then in the other islands of the Indian Ocean (Reunion, Mauritius, Mayotte) after hybridising with a Rubus native to Madagascar, R. roridus. It has also been introduced into north-eastern Australia, probably from Mauritius. It is also introduced in Burundi.
 

https://www.gbif.org/fr/species/2997267