Japan’s warm temperate forests are home to a truly unique saprophytic orchid species, Cyrtosia septentrionalis. The genus Cyrtosia is mostly from southern Asia, so this species is a northern outlier. In fact the name septentrionalis means “of the north”. It is lovely in flower and fruit and unique in many ways.
C. septentrionalis grows a leafless highly branched flower stalk to the height of 35-55 cm starting in late May, and by late June strange clusters of yellow and orange-brown flowers hang every which way off short lateral stems. Each flower is about 3 cm across. The lip is golden yellow and curled upward nearly clasping the column and thus forming a tube-like structure. Its upper surface is covered in fine bristles. The white column is long and descending, cradled by the curved lip. The sepals and petals are a uniform orange-brown color, sweeping backward in elegant lines from the flower’s front. The buds, ovaries, and backs of the sepals and petals are covered in a light pubescence.
After pollination, sometime in July, huge banana-like cherry red seed pods begin to form in hanging clusters and are fully mature by early fall. Each pod is 6-10 cm in length and covered in fine bumps. Inside winged seeds are formed and from what I can tell, the pods never truly split, hence the seeds within simply drop to the ground still within the pod. Presumably they germinate once the pod rots way. Being a saprophytic plant (or more exactly, an ectoparasite) it bears no leaves and has no noticeable green color.
This unique terrestrial orchid is found in moist woodlands in moderate to deep shade throughout Japan from Kyushu to southern Hokkaido (Sapporo). It is said to also be in Korea. The plant seems to prefer the rich evergreen broad leaf forests at lower elevations, ~300-500 m.
This was the first native orchid I ever saw in the wild in Japan. It was next to a trail on a popular mountain hike and even had a sign showing it was there! Since that day I’ve found it scattered about the mountains here and there, but never in any great number. It is a most peculiar orchid for many reasons. The following are a some things that make it unusual:
1. It is closely related to Vanilla orchids having huge bright red seed pods, hanging like crimson bunches of bananas. Clusters of flower buds also show the affiliation with the genus Vanilla.
2. The seeds within are very large winged affairs. Members of this genus have the largest seeds of all orchids (see pic with my grubby finger). The wing also is a unique feature.
3. It is an ectoparasite with no visible green parts (achlorophyllous). They live in close relationship with specific fungi and are in turn either using dead organic matter in the soil as a nutrient source or the roots of other plants.
4. While its flowers are large and showy, they difficult to see in a woodland setting. This seeming contradiction only makes sense when you see the plant in person.
It is easiest to find when in the fall when the fruit have matured rather than when in bloom, for despite their lovely coloration the flowers are difficult to see. The large bunches of banana-like fruit, however, can be seen from a great distance. Even the emerging flower stalk with its bunched buds is interesting and novel. In the old days it was used as a medicine (perhaps the seed pods), and was supposed to have a diuretic effect.
Here is a video of a forest where you can see this species in the wild – on a mountain called Tachibanayama, within the city limits of Fukuoka, Kyushu, Japan. You’ll see a fruiting plant starting at 5:30:
One other interesting story about this plant is its Japanese name, tsuchiakebi, meaning “earth akebi”. Akebi is a vine who’s Latin name is Akebia quinata, known commonly as “chocolate vine” in the west. A. quinata produces large purple-red fruits in the fall at the same time as the orchid. These fruits are a delicacy. Since the orchid’s fruits grow directly out of the earth with no leaves, it got the name earth akebia. I’ve seen no record of them being used as food however.
Though lovely, this species is not in cultivation due to its saprophytic nature. Technically these plants are in fact ecto (outside) parasites (living off another organism’s energy). To wit, the orchid lives off the fungus, and the fungus lives off dead organic matter or living plant tissues (most often roots). Research has been done to identify a least some of the fungus symbionts for this species. Perhaps one day if the fungus and orchid can be successfully cultivated together we can have these strange and beautiful plants gracing our gardens.