Microcitrus Inodora

There's not much published information about this rare species, first described by F.M. Bailey in 1889. It has a limited distribution in the north of Queensland, Australia, growing in lowland rainforest at the foot of the Bellenden Ker range, not far from Cairns.

In 1997 I was sent open-pollinated seeds from Riverside, USA, and had been happily growing them as Microcitrus Inodora, until I realised they didn't have paired spines. However, they are clearly different from all my other Microcitrus seedlings, with long, narrow leaves.
These seedlings are probably hybrids, so it will be interesting to see what the fruit are eventually like.

Since 2001, I have been growing seedlings which are clearly true-to-type, with prominent paired spines. I believe the seeds came from Australia, but I don't know the exact source.

"This new species of Citrus is well worthy of cultivation for its fruit, which is juicy and of equal flavour with the West Indian Lime. In general appearance the tree resembles the orange, having the same dark green foliage. I have chosen the specific name on account of all the flowers gathered being wanting in fragrance, a remarkable feature in a genus so noted for scented flowers."

Image is derived from a scan of the first collected specimen - the 'type specimen' - which is held in the Queensland Herbarium, and reproduced with permission. I have enlarged part of the twig so that the paired spines, a unique feature of this citrus, can be more clearly seen.

A drawing from the 1909 book by F.M. Bailey entitled 'Comprehensive Catalogue of Queensland Plants Both Indigenous and Naturalised'.

The fruit is described as oblong or elliptical, somewhat lemon-shaped, 5-6.5 X 3-3.5 cms and green when ripe.

The first photo of inodora fruit on the web! Taken of a wild specimen from Mt Bellenden Ker near Cairns in north Queensland, and sent to me by photographer Hugh Nicholson. See www.rainforestpublishing.com.au

There is a small specimen in the conservatory at Adelaide Botanic Gardens. The leaves on this plant lack the dark-green, smooth surface of the wild plant and of my seedlings. The fruits also appear smaller, yellower and less elongated than expected. However, an enlargement from the photo clearly shows the dual spines that confirm C. inodora.

Photos sent by Bruce Morphett, Technical Officer, Botanic Gardens of Adelaide, reproduced with permission.

Saga University, Japan, has been carrying out genetic research on citrus and microcitrus. These pictures of Inodora fruit are from their collection, with permission.

One of these seedlings flowered for the first time in May 2004, but all flowers dropped off without setting fruit.
I have now budded on to citrange rootstocks and hope for early fruit!

A photo sent to me by an Australian visitor to this web-site. It shows a rooted cutting bought from a Queensland nursery.
Notice the serrated, almost holly-like leaf margins.

A picture of inodora fruit at the University of California's Riverside collection. The yellow patches may be the result of sunburn. Notice the smooth edged leaves.

Finally, in early December 2006, the first mature fruit was produced - very small but beautifully formed, and probably a UK first!

These pictures are MUCH enlarged. The fruit was just 1.2cm long, about 0.6cms diameter, with a definite tendency to a hexagonal cross-section matching the internal segments. Taste - sour! Next year, perhaps, a bigger product.

From Riverside visitor Marc Harris comes this picture of a very seedy ripe fruit. Note the scale is in inches, so fruit is just under 2" or about 45mm long.