Tropicals & Tender Perennials: HOYA AUSTRALIS- a brief history, 1 by markroy68

markroy68 wrote:
TAXONOMY- Hoya australis is in the Hoya section pterostelma. Other members of this section are H. calycina, H. naumanii, H. albiflora, H. magnifica, and BSI-1 (syn. subcalva). H. albiflora and H. magnifica are often misidentified in cultivation. The specific epithet "australis" refers to the latin term for 'southern', not specifically to Australia.

Here are some brief descriptions of typical plants of the 5 subspecies:

ssp.tenuipies- this ssp. is always glabrous (leaves and stems hairless). The umbel (flower cluster) is loose and has clear white, starry flowers. The flowers are smaller and the pedicels thinner than ssp. australis. It comes from a moister environment than the other ssp. Flowers heaviest September to October in Australia, spring in the northern hemisphere.

ssp.australis- can be glabrous or pubescent (leaves covered with fine hair), the umbel is a tight collection of flowers that can be relatively small or large. Most specimens in cultivation are probably of this ssp. It is very variable, with many different leaf forms. Flowers heaviest March to May in Australia, fall/winter in the northern hemisphere.

ssp. sanae- pubescence varies but always pubescent. this ssp. is more xerophytic than the two above, but still viney. It has small quilted leaves that have recurved edges. Flowers May to July in Australia. It occurs on sand near the beach in Australia.

ssp.oramicola- Mostly glabrous with medium size rather succulent flowers, has bright green, more succulent leaves than sanae. It twines, and is not bush-like, it has thick quilted leaves. Flowers January to March in Australia where it occurs on red laterite soils

ssp. rupicola- Densly pubescent to glabrous, very succulent leaves, leaf edges not strongly recurved as in ssp. oramicola or ssp. sanae, is very xerophytic, and could be classified as a true succulent. The leaves are very thick and smooth, with no quilting. This subspecies along with ssp. oramicola has a slightly different floral structure than the first three, with short corolla lobes and calyx lobes visible from above between the sinuses. Flowers January to March in Australia where it occurs on sandstone.

I must thank David Liddle, who was kind enough to answer many of my questions involving the history, taxonomy, and distribution of Hoys australis. He also provided the photo montage which accompanies this post.