在台灣木本植物誌裡的松亞科松屬特徵裡提到:
松屬的葉子有兩種型態：原生葉與次生葉
原生葉螺旋狀排列且常退化為小膜質苞
次生葉針形,橫斷面半圓或三角形著生於短椏上
原生葉特寫—深褐色片狀螺旋狀排列於幼芽上
退化為小膜質苞–功能與芽鱗(bud scale)相同
原生葉腋下會長出短枝及針狀的次生葉，圖中可見短枝的幼芽
去除原生葉之後可見數個短椏的幼芽披覆深褐色鱗片
上圖中可見針狀葉基部開裂的鱗片
正常情況下短椏基部的鱗片包裹針狀葉的情形如上
這些鱗片好像會永存!
這即是短椏及短椏上的針狀葉(也就是次生葉)
圖中A 為長椏, B 為短椏
短椏圖形參考文獻
Morphology, anatomy and vasculature of leaves in Pinus (Pinaceae) and its evolutionary meaning
http://www.sciencedirect.com/science/article/pii/S0367253011001563
原生葉(primary leaf) 與次生葉(secondary leaf)可參考google 圖書內的內容
Illustrated guide to trees and shrubs: a handbook of the woody … – Google 圖書結果
books.google.com.tw/books?isbn=0486272583…Arthur Harmount Graves – 1956 – Nature – 288 頁
The primary leaves are usually small and scale-like and function as bud scales. But in the Pine, in the young seedling stage, the primary leaves are the only leaf …
The primary leaves are usually small and scale-like and function as bud scales. But in the Pine, in the young seedling stage, the primary leaves are the only leaf …
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