reprint from the old botanical blog. (originally published Nov.29th., 2011)
The image on f.43r could be read as a hedge formed from a single species, or a series showing a variety of forms for a particular (perceived) class of plants. Variations given the trunks and the underside of the canopy persuade me the latter s meant.
Some of these trunks pull up surrounding soil, others rise straight from the soil. Others again begin to form a trunk above ground level. All these variations occur among the mangroves, which also form an unbroken canopy in nature, and most importantly: mangroves form a ‘double’ set of roots.
The word mangrove is used in at least three senses: (1) most broadly to refer to the habitat and entire plant assemblage .., (2) to refer to all trees and large shrubs in the mangrove swamp, and (3) narrowly to refer to the mangrove family, the Rhizophoraceae, or even more specifically just to mangrove trees of the genus Rhizophora.
To see it in nature, and the impression of a translucent line running across them, try this link.
The second line of roots actually rises up through the water from below tidal mud. The roots are known as breathing roots (pneumatophore); an especially fine picture is here. In addition, this shows the usual density – a caution for boats.
correction for clarity (8th Nov 2014)
So, as I read the drawing, the straight(-ish) line separating the two series of roots marks the waterline shoreline. So, as I read the drawing, the straight(-ish) line separating the air from the ground level marks the shoreline. And I read these roots in the same way, with that other straight (-ish) line – i.e. between the first and second tier of roots – marking the waterline.
All mangroves have similar leaves – similar to the drawing on f.43r and similar to each other though the number of mangrove species is staggering. This ‘harlequin’ effect appears elsewhere in the botanical section and appears to refer to leaves having one side noticeably lighter than the other.
Species including Rhizophora stylosa create a mound about their roots. Others considered mangroves – such as Avicennia alba – do not.
For a database of mangroves native to the region around Malaysia (mod. Nusantara), the site linked below is excellent. (G/translate is adequate).
Sonneratia alba was widely traded out of east Africa, to as far as Oman or north-west India.
As this map shows, though, mangroves are found across much of the world, and not all the same species occur together. The type found in east Africa are different from those in Malaysia, India or Southeast Asia.
I hope this general identification may do; if anyone else cares to identify the flower more exactly, I’d be glad to hear.
Traditional uses for mangrove trees include: building houses, fences,walls,and furniture, and for carving.
In traditional medicine, roots, bark and leaves are used. The same parts were used for tannin used as preservatives and stains in leather work. Through Polynesia to East Africa (including Samoa), the roots provided the black dye used in tapa cloth (also known as siapo in Samoa). The flowers are used in garlands. Some mangrove flowers yield an oil which has been used in perfumes. I have not researched the origins, extent or antiquity of that use.