Hibiscus macilwraithensis.
Previously known as Macrostelia grandifolia subsp. macilwraithensis it is now commonly known as Macrostelia.
They are native to coastal areas of N.E. Queensland and other northern states.
They are shrubs up to 4 or 6 m high with brown lenticels on the lower woody stems.
Younger pale green stems have pale brown stellate hairs.
The alternate leaves are on petioles up to 3 cm long with paired stipules at the base.
The linear stipules, 0.5 to 1 cm long have a few stellate hairs.
The ovate to obovate blades are up to around 18 cm long and 5 cm wide.
The blade has a pointed tip and tapers gradually to a heart-shaped base.
Both surfaces of the blade have at least a few simple and stellate hairs.
Inflorescences are mostly a single axillary flower but there can be a small terminal cluster.
Flowers are on a pedicel up to 5 cm long with dense stellate hairs.
There are 6 or 7 green involucral bracts in the epicalyx.
They are free or joined at the base for a mm or two.
Up to 12 mm long they have a few stellate hairs.
The tubular calyx, up to 1.5 cm long has 5 lobes on the rim.
The lobes have stellate hairs on the outer surface.
The 5 overlapping, up to 3 cm long petals have a narrow base and a wide flattish tip.
The flowers do not open fully and are up to 3 cm across at the top of the corolla.
The white to cream petals have stellate hairs on the outer surface especially around the edge.
The filaments of the around 20 stamens are fused into a staminal column.
Just below the top of the column the anthers are attached to the free 3 or 4 mms of the white filaments.
The kidney-shaped anthers open outwards through longitudinal slits.
From the top of the superior ovary the 2 to 3 cm long style passes through the staminal canal.
Just outside the canal it splits into 5 branches each with a white stigma lobe.
The fruit are slightly flattened spherical capsules with the calyx and epicalyx still attached.
Capsules, up to 1.5 cm have a lot of pale brown stellate hairs.
The numerous seeds in the 5 chambers are covered in simple white hairs.
J.F.
