Plant story

Ixia mostertii

 

Name: Ixia mostertii M.P. De Vos
Family: IRIDACEAE – subfamily. Ixioideae

The Breede River Valley is well known to many visitors for its fine wines, fruits and beautiful mountains. Not as well know but just as beautiful and fine is a bulbous geophyte Ixia mostertii which occurs on clay sandy soils in the valley.
Ixia mostertii is named after Louis Mostert, a keen and interested landowner in the Wolseley area.
Ixia mostertii is a beautiful cormous geophyte. The flowers vary from pink to purple with a dark star-like centre. The flowers are closely packed at the end of the branches. The perianth tube is funnel shaped.  The leaves are linear to sword-shape with prominently thickened veins and margins. The flowers are spirally arranged on a spike with 5- 12 flowers closely packed at end of stems. The tube is slender, thread-like. The rootstock is a globe-shaped corm and is surrounded by fine to moderately coarse fibres. The plant grows up to 45cm high.
Ixia mostertii distribution range is from Romans River to Worcester. It is only known from three localities. This species occurs in Breede alluvium Fynbos vegetation type or Breede alluvium Renosterveld. Renosterveld vegetation type is one of South Africa’s most threatened vegetation types, with little more than 5% left. Renosterveld and Breede alluvium fynbos is a type of Fynbos and is part of the Cape Floral Kingdom.

Very little information is available regarding the ecology of Ixia mostertii. It has a dark star- like centre and the perianth tube is narrow and closed, looking at this floral morphology it indicates that they are pollinated by beetles. The perianth structure is similar to other Ixia species that are pollinated by the monkey beetle. 
Ixia mostertii has been listed as Endangered because it is a highly restricted species and it has lost a considerable amount of habitat in the past and this is likely to continue. The biggest threat is agriculture and urban development. The habitat of Ixia mostertii needs to be protected. None of the existing populations occur within a protected area. The Stewardship Project, an initiative to encourage landowners to commit their valuable natural land to conservation, has been actively involved in the area where this species occurs to try and save this plant from extinction. The Millennium Seed Bank has also collected seeds of this plant to safeguard it from extinction.  

Story by Olivia Pekeur

SANBI, Kirstenbosch National Botanic Garden
Cape Town
Republic of South Africa