Weeds in farmlands

Because of some occasion, I need to get contact with the weeds found in the farmlands and also assess their harmfulness to the crop. I was surprised by the diversity of the weeds as the weed composition is quite different in different timing of a year, and also the beauty of them. They are actually not common in Hong Kong as they are mostly restricted to the farmland areas. Some of them are even locally rare. However, farmland in Hong Kong is shrinking which may affect this diversity. I wonder if there is anyone care about this.

Machilus kwangkungensis

Genus Machilus Nees (Lauraceae)
A small genus in Lauraceae consists of about 100 species, mainly distribured in tropical and subtropical South and Southeast Asia. Most of them, ca. 85 species, are in China including 12 species in Hong Kong.

Machilus kwangkungensis is a rare and restricted species in Hong Kong where it is only found in Ho Sheung Heung and Kwu Tung, located at the Northern part of Hong Kong. It is indeed a narrowly distributed species which is restricted to a few provinces in the mainland, including Guangdong, Guangxi, Guizhou and Hunan. In other words, the population in Hong Kong is nearly at the southern extreme of the range of this species. Identification of Machilus is very hard as many of them are morphologically very similar.

Brown Crake (Amaurornis akool)

Brown Crake is probably a rare resident or irregular visitor to Hong Kong that was found breeding in Hong Kong. Its occurrence would attract crowd of people to visit it and photograph it. Disclosure of its location would bring pressure to not only the bird, but also the residents operating the fish pond. Birdwatchers or bird-photographers should respect and understand the others in order to establish a positive image for themselves. It's all about self-discipline.

Ardisia pusilla

Genus Ardisia Swartz (Myrsinaceae)
A large and widespread genus consisted of about 400 species distributed in tropical and subtropical regions of the world. 65 species are in China including 14 native species in Hong Kong. Their nature varies quite a lot while some like A. hanceana are shrub that may reach 3 m tall but the one shown in the above picture is small shrub that can only reach about 30 cm tall.

Ardisia pusilla is uncommon but quite widespread in Hong Kong that you may find it on Hong Kong Island, Lantau Island and in the New Terrestories. It grows mainly along stream banks under evergreen forests. Canopy cover should be complete enough to avoid too much sunlight reaching the place where they grow as a moist and shaded environment is required.

Castanopsis fordii

Genus Castanopsis Spach (Fagaceae)

A fairly small genus composed of about 120 species over the world. It is mainly found in South East Asia where China contains 58 of them and there are 10 native Castanopsis in Hong Kong.

Castanopsis fordii is widespread in South East Asia which is recorded in 8 provinces in the mainland China and also in Thailand and Vietnam. However, it is rare in Hong Kong as there is only a few localities of the species and the population sizes keep very low. One reason for its rarity might be because of its domestic and economical use. It was previously used as fuelwood and its populations in Hong Kong might be heavily harvested in the past during the second world war. Finding of C. fordii in Hong Kong would be a hard work nowadays.