Aeschynanthus acuminatus（芒毛苣苔 ● Acuminate basket vine）

Aeschynanthus acuminatus is a climber found on rocks besides steams. The species is quite common in dense and mature forests all over Hong Kong. The plant is characterized by its thick and opposite leaves and its somewhat white branches.

A. acuminatus flowers in winter or early spring. In this February, I took a hike in the Tai Mo Shan area and met a colony of the plant. Unfortunately, the flowers are half-withered but I still managed to take a few pictures of them. After some comparison with the photos on the internet, I made some interesting observations and hypotheses.

Observations:

1. The flowers have a quite peculiar shape with didynamous stamens extending way out of the corolla tube.
2. The female reproductive structures mature after the stamens wither.
3. The drawing and description in Flora of Hong Kong suggests that the stamens are longer than the pistil. In reality, the pistil will elongate after the stamens wither to the original position of the anthers.
4. The withered stamens seem to contain some kind of viscous liquid after it withers; I suspect that the liquid is some kind of nectar, but I'm not sure whether it is secreted by the stamens or did it simply flow out from the flower.

Hypotheses:

1. The flowers should be insect pollinated 
2. The anthers stick the pollen on the abdomen of the pollinator. After the stamens wither, the stigma elongates to collect the pollen from the same position of the pollinator.
3. Guaranteed cross pollination by different maturation periods of male and female reproductive structures
4. Judging by the position of the stamens and the elongated pistil, the pollinator should have a fairly large body size. The winter flowering time and its mature forest habitat limits the choice, probably bees in the genus Bombus?

*Update: after further discussion is hkwildlife,net, it was suggested that the elongated pistils have already been fertilized. The possibility of pollination by birds can also be explored in the future. 

Here are some photos showing the withering flowers. Hope I'll meet fresher flowers and the plant's pollinator next time.

Pistil elongated flower

Cropped image showing possible nectar secretion

Front view of flower

leaves

Sophora tomentosa（絨毛槐 ● hairy sophora）

Sophora tomentosa is a tall shrub species that can be found on beaches and places near the coast. The speices is rare in Hong Kong and can only be found in several outlying islands or beaches in the Sai Kung district. Although rare locally, S. tomentosa is distributed worldwide. The shrub is characterized by its dark green compound leaves with recurved leaf margins. The leaf shape and the hairs on the leaf may be used by the plant to tolerate the rather harsh conditions near the seashore. The plant produces yellowish green pods in winter, the shape of the pods gives the species and its varieties another name -- the necklace pod. I am quite curious about how the pods disperse. They seem too large for a bird to consume, maybe the pods could float on the sea across outlying islands? I will try to examine the pods next time I see them.

Flora of Hong Kong states the flowering period as mid-summer and the fruiting season as winter, but flowers and fruits are both observed during my visit to the plant in mid-December. Here are some photos taken from a beach in Sai Kung.

Plant on sandy beach

Dark green leaves

Hairy abaxial leaf surface

Yellowish flowers 

Yellowish flowers

Necklace-like pods

Necklace-like pods