Agati tomentosa (Hook. & Arn.) Nutt. ex A.Gray
Sesbania arborea O.Deg. & I.Deg.
Sesbania hawaiiensis O.Deg. & I.Deg.
Sesbania molokaiensis (O.Deg. & Sherff) O.Deg. & I.Deg.
Common Name: Ohai
Sesbania tomentosa is a variable species .Usually a low, spreading shrub with horizontal or arching branches that can be more than 14 metres long, it can also adopt an erect, tree-like habit, growing 2.5 - 6 metres tall. In the wild, a single, prostrate plant can cover an area of many square metres, but in cultivation it will tend to be under 3 metres in diameter[
The plant is an exellent ground cover and soil stabilizer in coastal areas and can also be grown as a hedge. The large striking flowers make this species suitable for ornamental use, especially in maritime conditionst[
Sesbania tomentosa used to to be widespread in dry areas at elevations below 750 metres on all of the main islands of Hawaii. However, destruction of these habitats by means such as off-road vehicles, habitat disturbance, residential development in coastal areas, cattle & goats, has greatly diminished its natural occurrence within its former range. The plant is classified as 'Endangered' in the IUCN Red List of Threatened Species[
North-central Pacific - Hawaii
Calcareous and sandy beaches, dunes, soil pockets on lava, rocky ridges and slopes, along pond margins, dry shrublands or (rarely) dry forests, on basaltic and calcareous substrates; at elevations up to 540 metres[
|Other Uses Rating
|Cultivated, Ornamental, Wild
Prefers a sunny position and a well-drained, light-textured soil[
]. A xeric plant, growing best in dry conditions and generally tolerant of strong winds and salt spray[
]. Established plants are drought tolerant[
This species is endemic to Hawaii, where it is endangered, but it has also become established as an escape from cultivation in Puerto Rico and reportedly elsewhere in the tropics[
Tree or tall bush forms with top heavy growth may need to be staked in order to prevent them toppling over due to the wind, especially if they are grown in softer (i.e. loamy, sandy) soils. Too much water and fertilizer (especially with extra nitrogen) may be the culprits for this luxuriant growth[
On sunny days the leaf clusters at the stem tips have a fragrance that resembles the scent of nectarines[
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[
All species in this genus have potential for use as soil-improving ground cover plants that can greatly reduce soil erosion[
Prostrate forms of this species can be used as a groundcover, and are particularly effective in preventing erosion in many coastal areas[
Shrubby forms can be grown as hedges, whilst tree forms can make a tall hedge or a screen[
The flowers and seeds are used in crafting beautiful Hawaiian leis[
Seed - it has a hard seedcoat and may benefit from scarification before sowing to speed up germination. This can usually be done by pouring a small amount of nearly boiling water on the seeds (being careful not to cook them!) and then soaking them for 12 - 24 hours in warm water. By this time they should have imbibed moisture and swollen - if they have not, then carefully make a nick in the seedcoat (being careful not to damage the embryo) and soak for a further 12 hours before sowing.
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