Hydnophytum- Part 9

For some reason, this does not look like a typically antplant. The basal tuber is not large relative to the leaf, there are few signs of ant entrance holes or looks like it can house ants. The tuber is also hairless or thornless. This is Hydnophytum simplex. The epithet simplex is probably means simple in Latin... but my google search gives veneral disease - herpes simplex and simplex as in geometry. Nevertheless, anything that comes from Aru Island off New Guinea in the Arafura Sea is rare in cultivation and very exotic. The attractive bright red berries in the insert is borned on a "branch" like cauliflory or "stem flower".

With big leaves and photosynthetic green tubers it likes ample water however, it is surprisingly tolerant of water stress. It does not shed leaves in response to drought. Instead the leaves curl-up and young leaves develop permanent deformity if water stressed.

Hydnophytum Sp hairy flowers - Part 8

I thought this would be just another H. moselayanum variant. Was lucky to be visiting my friend in southern Taiwan just when he returned from a trip to Jakarta. He brought back goodies (some ant plant seedlings) and offered me to pick a few. They were deemed to be of 1 type. Actually, the seedlings are most indistinguishable. I just picked 3 most dissimilar plants... and it turned out that one of them is really different. This one has got hairy flowers. And not only that the leaves and internodes are longer compared to other H. moselayanum under similar exposure to sun and watering regime. While free-flowering, it seems to be less self-fertile. Perhaps it is still a yound plant and sexually immature. The tuber has entrance holes "raised" like an annulus. It will be another one of those interesting species in need of locality data!

Hydnophytum Sp - Part 7

This is a very interesting H. formicarum look alike. The tuber ridging and color resemble H. formicarum from Singapore. Well, the leaves are much bigger almost 10 cm long and 7 cm across. The leaf resembles some of the shrubby Ixora sp which is also incidentally from Rubiaceae. We have yet to see mature berries and like H. formicarum aborts easily during windy and dry weather.

This specimen comes from the island of Halmerhara, the largest island in the Maluku group. One would expect it to possess more xeric characteristics given its geographic location lies between much larger island of Sulawesi and New Guinea on the monsoonal zone. Large floppy leaves are kind of ill-adapt for seasonal climate, we are not prepared to allow it to shed its leaves at this point until we get more seedlings.

Hydnophytum - Part 6

A picture is worth more than a thousand words: the leaves of various Hydrophytum sp. in the formicarum - moselayanum complex placed side-by-side. Noticeably, the lateral veins are more prominent in the formicarum and leaf thickness increases towards moselayanum.

Trying to justify back-dating this posting; this jpeg composite was created way back in mid-Jan 2008.

Hydnophytum - Part 5 (moseleyanum)

This is a composite picture. Click and open in new window for an enlarge version.

Clockwise from the top: (1) Commonly traded species in US (2) Sp from Papua, ex Botanical Gdn, Europe (3) Sp from Northern Australia ex Botanical Gdn (4) 2 Sp from Triton Bay, Irian Jaya.

The commonly traded species has been identified as H. moseleyanum (syn. H. papuanum) and is also almost identical to the species from a Botanical Gardens in Europe collected in 1960s or 1970s from New Guinea. They have matt lime-green semi-succulent leaves and silvery brown tubers. The species from Northern Australia is also similar but is more deciduous under the same cultivation regime. It shreds leaves easily when dry. Finally, 2 species from Irian Jaya looks more intermediate just like the other H. aff. moseleyanum from the Philippines and Bogor, Java. These 2 irian plants differs in having longer pointed leaves.

Maybe it is more practical to define this group as a formicarum-moseleyanum complex rather than to pin a name to it.

Hydnophytum - Part 4 (aff. moseleyanum)

I started off by introducing Hydnophytum with affinities to H. moseleyanum without introducing H. moseleyanum. Why? The reason will be obvious in part 5. Here, i have taken the liberty to label those which have the H. moseleyanum look but are found outside and farway from New Guinea.

The above species comes from the Philippines. Like the former Bogor plant, it has semi-succulent leaves stacked closely together and the veins are not prominent.

Hydnophytum - Part 3 (aff. moseleyanum)

You may now notice a trend of featuring Hydnophytum from west to east. I am trying to show the variation of Hydnophytum species complex; some may be distinctive enough to be a species on its own while others are just too fluid and form a continuous change from formicarum to moseleyanum from Sumatra to New Guinea.
This one comes from Bogor, Java. However, i'm hesitant to say that it is from Java because it actually comes from Bogor Botanical Gardens. What's the chances of picking up dropped clump of hydnophytum seedlings during a garden stroll? This is probably the most interesting species amongst hydnophytum with great horticultural potential. The leaves are relatively small, shiny and a bit succulent. The branches are short and would form branchlets. The caudex is also very smooth, silvery green and shiny. And for the best part, the caudex grows faster compared to say H. formicarum and even H. moseleyanum. It is relatively tolerant of low humidity and burst into caudex growth when it is given generous watering. Well it definitely has more affinities to H. moseleyanum.

Hydnophytum - Part 2 (aff. formicarum)

Continuing from Part 1, this species comes from the island of Borneo. It is really similar to H. formicarum in Part 1, except for the generally smaller stature and having linear leaves. It is definitely a slower plant compared to H. formicarum type and it has to start off life with a smaller seed too.

Hydnophytum - Part 1 (formicarum)

I wonder if anyone has heard of antplants? Okay, there will always be ants around plants looking out for food - coaxing sugary secretions from mealies, feeding on nectar rich flowers, collecting sweet secretion from nectary glands on leaves giving some protection to Impatiens. More specifically, i shall refer to antplants as plants that provide a home for the ants. The family Rubiaceae has a few highly evolved genus - Hydnophytum, Myrmecodia, Myrmephytum Anthorrhiza, Squamellaria which provide a complex honeycomb structure for housing ants! These plants have a fat stem base or "caudex" that can house ants, and in nature antplants are invariably populated with ant colony. In cultivation, these plants also develop a caudex irrespective of whether ants choose to migrate or live there. There is a symbiotic relationship between plant and ants. Ants provide nutrients and at the same time protect antplants from its insects or even human enemies. While the antplant provides a shelter for ant colony. Well, i don't want to go into the details but Nick Plummer has a good website that covers this topic with a reference list.

Hydnophytum is the genus with the widest distribution from Fuji Islands in the Pacific to Andaman Islands in the Indian ocean and from Southern Indochina to Cape York in Australia.

Let's start off with the better known Hydnophytum formicarum (photo above). This plant is in cultivation in both private and botanical collections for sometime. Various distinctive forms or varieties are available from specialist nurseries time to time and they are mostly labelled as H. formicarum. Personally, these are probably variations of one species complex or have evolved into different species from west to east. Base on regional flora, Hydnophytum represented by one species which is H. formicarum in Andaman Islands, Peninsular Thailand & Malaysia, Sumatra. Observations of wild H. formicarum plants in Peninsular Malaysia and its offshore islets in the South China seas yield little variation. Thai plants are also similar. The leaves are leathery and have prominent veins, tubers are invariably dark brown with ant entrance holes irregularly placed. The "spination" or "bristles " covering the tubers are root stubs which stop growing. Tuber ridges and lobings are irregular. Having seen many seedlings from the same mother plant, the caudex is shaped more by environment conditions then genetics. More to come... in Part 2.