後山紅葉 Maple at Backyard
<Scroll down for English version>
"片片紅葉轉..." 後山有一棵高大的紅葉樹，她的名字叫『烏桕』。
香港紅葉
提到香港觀賞紅葉的聖地，非大棠莫屬。那裡有一處地方人工種滿了密密麻麻的楓香。但大家知道本土的紅葉樹有哪些嗎？常見的有烏桕、山烏桕、野漆。這些本土紅葉樹在郊野自然而零散地分佈，比起密集的“大棠模式”，後山的『萬綠叢中一點紅』又是另一種風情。
枯葉或新葉為什麼會變紅呢？簡單地說，就是葉內沒有足夠葉綠素，而顯現出胡蘿蔔素和花青素的橙色或紅色。
名字的由來
Sapium sebiferum 是烏桕的學名。在網上有關於“Sapium”的字源：
1. (Celtic賽爾特語) Sap: Fat油脂；
2. (Latin拉丁文) Saponis: Soap肥皂。
而"Sebiferum"意思是“具脂蠟的”。
這些字詞都顯示出烏桕的一些特性，如種子外皮有蠟燭(桕蠟)和肥皂(皮油)的原料，種子可壓榨“青油”。英文名Chinese Tallow Tree的“Tallow”更是動物脂肪的意思。霎時覺得烏桕非常"油淋淋"(油膩)。
中文名『烏桕』則著重描述其形態特徵，《本草綱目》中記載 “烏喜食其子，因以名之；其木老則根下黑爛成臼，故得此名”。
古人眼中的烏臼鳥
“烏”(烏臼鳥) 究竟是什麼雀鳥？有興趣可點擊下面的網址，看看其他人的討論及古人的描述。或許是『黑卷尾』，但個人認為是『髮冠卷尾』。
關於烏桕的詩詞其實不少，如明代詩人楊慎的《征人早行圖》中的一句：杜鵑花下杜鵑啼，烏臼樹頭烏臼棲。
認識身邊的植物，讀讀詩句，感受文人雅士筆下的智慧，也是研究生態的樂事呢？
參考資料 Reference（請衡量非官方資料的準確性）
<Maple at Backyard>
There is a Chinese Tallow Tree at the backyard of Siu Sai Wan. In winter, the leaves of this tree turn red before falling.
Tai Tong is located at Tai Lam Country Park in Hong Kong and it's famous as the intensive plantation of Sweet Gums at roadsides. The Sweet Gum is native and leaves turn red in autumn and winter. However, the Sweet Gun does not belong to the family of maple trees that grow in Canada and Japan.
Other most common native "red-leaves" trees are Mountain Tallow Trees, Chinese Tallow Trees and Wax Trees.
Why do leaves turn red? We can simply conclude that there is not enough Chlorophyll (green pigments) in the new leaves and old leaves.
The scientific name of the Chinese Tallow Tree is Sapium sebiferum. “Sapium” may originally come from Celtic "Sap"(means fat) or Latin "Saponis" (means Soap). And "Sebiferum" means Wax.
The Chinese name "Wu Jiu" was described in a famous Chinese medicine book Compendium of Materia Medica in the 16th century. It said that a bird called "Wu" likes to eat the Chinese Tallow Tree's fruits and "Jiu" means its rotten wood.
But what is the bird species of "Wu" today? It can be an interesting topic to discuss. I guess "Wu" is the Hair-crested Drongo according to the old Chinese poems.