◆◇院區植物介紹專欄◇◆ 院區植物介紹 Discovering our campus plants 蘇鐵與台東蘇鐵 陳建志、趙淑妙 蘇鐵與台東蘇鐵最主要的辨別特徵，在於蘇鐵的小葉邊緣反捲， 而台東蘇鐵的小葉邊緣扁平不反捲。 兩者是同一家族的︰屬裸子植物（特徵︰胚珠裸露，無良好的保 護器官或構造）的蘇鐵目（Cycadales; 俗名︰cycads）。被子植 物（通常會有艷麗花朵的植物）的胚胎在發育的過程，會在一個類 似「子宮」的組織構造（或器官）中生長，並受到保護。這種器官 稱做「子房」；子房壁在種子成熟後發育為果皮和果肉（但有些被 子植物的果肉則不明顯）。 "Cycads" 是源自於希臘文的椰子樹名，因蘇鐵類植物常被誤認 為棕梠樹或是蕨類植物。其實他們和後兩者沒有親戚關係。蘇鐵類 植物的精子具有許多鞭毛，這在現生的種子植物中相當獨特。蘇鐵 類植物出現在古生代的二疊記（約二億八千萬年前），在中生代的 侏儸紀（二億到一億五千萬年前）達到他們家族興旺的巔峰。由化 石的研究已確認蘇鐵類植物在過去無論在種類和分布上都比現在更 多且廣，目前則僅有小的族群在各大陸塊上呈不連貫的分布。可說 是古老的孑遺植物。 Sago palm and Taitung cycad The major differences between Sago palm and Taitung cycads are their leaflets. The former can be distinguished immediately from the latter (and most other Cycas) by the strongly revolute margin of its leaflets. These two taxa belong to the gymnosperms (characterized by the naked ovules, out of which there is no specialized organ). In contrast, the angiosperms (usually characterized by showy flowers) have a uterus-like organ, which nourishes the fertized ovule and protect embryo. This particular organ is called "ovary", which will develop into a fruit. Cycads are often wrongly linked to palms and ferns. In fact they are not related to either. Within the living seed plants they are nearly unique in that they produce motile sperm cells. Cycads flourished in eons past and reached their peaks in the Jurassic Period of Mesozoic Era some 150-195 million years ago (Stewart & Rothwell 1993). According to the fossil survey, it is certain that cycads were more varied and profuse in earlier times and more widely distributed. Today cycads may be regarded as relics comprising small populations distributed disjunctly on many continents (Jones 1993). 蘇鐵（又名鐵樹、鳳尾蕉、避火樹） 英文名：Sago palm 學名（Scientific Name）：Cycas revoluta Thunb. 科名（Family）：蘇鐵科CYCADACEAE or Cycad family 分 布：分布於日本、中國大陸。台灣全島栽培。院區於各所門 前多有栽植。 形態特徵：常綠灌木，一回羽狀複葉，狀似棕梠，小葉線形，先端 刺尖，基部兩側不對稱，葉緣顯著反捲，葉背有絨毛。 雌雄異株，雄花序圓柱形，雌花序為圓球形；種子橢圓 形至扁橢圓形，成熟時橘紅色或紅褐色，沒有橫向細紋， 密生灰黃色短絨毛，但會逐漸脫落。本屬植物根據記載， 全世界約30種。分布於亞洲、澳洲、太平洋島嶼、非洲 東部、馬達加斯卡島的熱帶及亞熱帶地區。台灣自生僅 有一種,，即台東蘇鐵。蘇鐵幹中薄壁細胞含有多量澱 粉可供食用，俗稱西米（Sago）。因長得像棕梠樹，英 文俗稱為Sago palm。 Distribution: Japan and China. The most commonly cultivated cycad in the world. Characteristics: Evergreen shrubs. Leaves simple pinnate, with linear leaflets, pungent apically and asymmetry at the base, margins remarkable revolute, tomentose beneath. Dioecious, male inflorescence cylindric; female inflorescence ovoid. Seeds ovoid to ellipsoid, compressed, orange-red or red-brown when mature, without diminutive horizontal wrinkles, when young densely gray-yellow tomentose but becoming glabrous gradually. The genus Cycas, with 30 species, mostly distributes in tropical and subtropical areas of Asia, Australia, Pacific Islands, Eastern Africa and Madagascar. In Taiwan there is only one native species, Taitung cycad. There are abundant starch in parenchyma cells of its trunk. People called this kind of starch "western rice". The crown of cycad is like palm, so its English common name was given "Sago palm". 台東蘇鐵 英文名：Taitung cycad 學名（Scientific Name）：Cycas taitungensis C. F. Shen, K. D. Hill, C. H. Tsou & C. J. Chen 科名（Family）：蘇鐵科CYCADACEAE or Cycad family 分　　布：台灣特有，產於台東。院區栽於植物所門前。 形態特徵：常綠樹木，高約2公尺，稀可達5公尺；一回羽狀複葉， 小葉線形，先端刺尖，葉緣不反捲，幼嫩階段密部長毛， 成熟則逐漸脫落。雌雄異株，雄花序圓柱形，雌花序為 圓球形；種子橢圓形至扁闊橢圓形，成熟時橘紅色或深 紅色，新鮮時種皮上有橫向細紋。 這一屬，台灣自生的僅此一種。產於台東，為農委會正式公告列 名保護的珍貴稀有植物。 Distribution: Endemic in Taitung County. Cultivated in the front of the Institute of Botany. Characteristics: Evergreen trees, ca. 2 m high, rarely to 5 m. Leaves simple pinnate, with linear leaflets, pungent apically, margins flat, non-revolute, lower surface covered with long glandular hairs in flushing stage, often becoming glabrous with age. Dioecious, male inflorescence cylindric; female inflorescence ovoid. Seeds oblong-ovoid to ellipsoid, slightly compressed, orange-red or dark-red when mature, densely to loosely pale brown- tomentose, with diminutive horizontal wrinkles even when fresh. This species is also the only member of Cycas that endemic in Taiwan. It is formally announced as an endangered, rare, and protected species by the Council of Agriculture, Executive Yuan. 蘇鐵（又名鐵樹、鳳尾蕉、避火樹）　　　　　　台東蘇鐵