Humbertia

Humbertia madagascariensis forms a medium-sized tree up to {{convert|30|m|ft|-1|abbr=on}} tall. The trunk often has small buttresses and is straight and cylindrical, up to {{convert|200|cm|ft|1|abbr=on}} in diameter. The outer bark is greyish-brown, with fine cracks, and the inner bark has whitish bands. The twigs bear prominent leaf scars and are covered in reddish hairs when young. The leathery, hairless leaves grow at the tips of the twigs and have short stalks. They are up to {{convert|10|cm|in|0|abbr=on}} long, obovate, with entire margins, cuneate bases and notched or obtuse apexes. The small flowers have parts in fives and grow in the axils of the leaves, either singly or in small groups. The petals are creamy-white and hairy on the outside with membranous edges. The stamens and pistil project in a boss and are more than twice as long as the corolla. The fruit is a slightly fleshy brown berry containing one or two seeds.{{cite book|author=Lemmens, R.H.M.J.|author2=Louppe, D.|author3=Oteng-Amoako, A.A.|title=Timbers 2|url=https://books.google.com/books?id=4MpmAgAAQBAJ&pg=PA396 |publisher=PROTA |isbn=978-92-9081-495-5 |pages=396–398}}

The lowland forest in the east of Madagascar where this tree is found includes such characteristic species as Myristicaceae, Anthostema, Protium, Allantospermum, Magnistipula, Chaetocarpus, Tsebona macrantha, Perriera and Dialyceras. The birds living in this evergreen woodland include the brown mesite, the Madagascar serpent eagle, the scaly ground roller, the dusky tetraka, the red-tailed newtonia, the helmet vanga and the Bernier's vanga.{{cite book|author1=Safford, Roger |author2=Hawkins, Frank |title=The Birds of Africa: Volume VIII: The Malagasy Region: Madagascar, Seychelles, Comoros, Mascarenes |url=https://books.google.com/books?id=qaFLAQAAQBAJ&pg=PA19 |year=2013|publisher=A&C Black|isbn=978-0-7136-6532-1 |page=19}}

The timber — known as {{lang|mg|endranendrana}} or {{lang|mg|fantsinakoho}} — is extremely dense, hard, and durable, making it well-suited for heavy construction work, especially where it will be exposed to wet conditions. It can also be used for parquet flooring, sculptures, turning, mine props, railway sleepers, and agricultural implements. However, the tree has a limited range and has become rare, and is therefore in need of further research and protection.

A sesquiterpene alcohol of a new type has been isolated from the heartwood of the tree, and the class of sesquiterpenes of this type has been given the name humbertiol.{{cite book|author=Eich, Eckart |title=Solanaceae and Convolvulaceae: Secondary Metabolites: Biosynthesis, Chemotaxonomy, Biological and Economic Significance |url=https://books.google.com/books?id=ZpYtUED_DSsC&pg=PA356 |year=2008 |publisher=Springer Science & Business Media|isbn=978-3-540-74541-9 |page=356}}

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Category:Convolvulaceae

Category:Monotypic Convolvulaceae genera

Category:Endemic flora of Madagascar

Category:Flora of the Madagascar lowland forests

Category:Plants described in 1786