Salt crystals on Acanthus leaf

Acanthus sp. (老鼠簕) is a typical coastal plant. It lives in a salty environment. Yet the plant can not tolerate (抵受) too much salt. Fortunately nature has solved its problem. On the dorsal side 背面 (the side facing sky rather than ground) of its leaves, there are many special salt glands (salt-secreting glands). These are groups of cells that remove, by secretion (分泌),  any excess salts from the plant. Hence, the tiny white crystals seen on leaf surface are mainly Sodium chloride. Their similar size and random distribution correlate with the position of the salt glands. A free-hand section in the laboratory may reveal their presence.  I myself tasted the salt crystals before, however, those under the age of 18, please seek advice from your guardian before any similar attempt.

Go to the Acanthus page.

Droppers of Kandelia (水筆仔)   Kandelia page

Kandelia is a very common species in Hong Kong. It is biologically interesting. Before its fruit disperses, the seed is already germinating while still attaching to the parent. In the photograph,  the remaining sepals of the flowers are still intact. The conical seedling that looks like a Chinese calligraphy brush head is green (on the outer layers) and therefore photosynthetic. [Advanced learner : It is the hypocotyl, the growing stalk beneath the cotyledon.] As the droppers fall on muddy shore, they can easily gain a foothold. When  their roots grow and branch, they help trap muddy sediments and organic matter, and in the course of time, contribute to the process of coastal reclamation. There are other mangrove species in Hong Kong, together they form a mangrove community.  Go to the Kandelia page.

　Go to the Kandelia page.

Go to the Bruguiera page

Go to the Excoecaria agallocha page

Go to the Mangrove in Phuket page