《史記》記載，漢朝時，張騫出使西域，引進苜蓿；而一般認為約在公元前六世紀，苜蓿從波斯傳入古希臘地區。羅念生與王煥生所翻譯的荷馬史詩《伊利亞特》，提到阿基琉斯(Achilles)的馬吃的草之一是「苜蓿」：「馬在車旁吃沼澤裡的苜蓿和芫荽(Iliad, Book 2: Line 776)。這與傳說中汗血馬吃的苜蓿一樣嗎？它是苜蓿屬植物中最著名的紫花苜蓿(Medicago sativa)嗎？本文將重新整理荷馬史詩中希臘原文λωτός 一字的可能意涵，爬梳中文文獻中苜蓿相關的典故，整理中國引進紫花苜蓿的歷史脈絡，比較分析中國詩詞中苜蓿的意象，以及苜蓿文學意涵的轉變。從這些分析討論，本文推論苜蓿東傳中國、西傳希臘的可能脈絡與意義。本文分析結論是，荷馬史詩《伊利亞特》中馬吃的草可能是苜蓿屬植物或是其它科植物，但不是從波斯引進古希臘地區的紫花苜蓿；儘管如此，苜蓿的引介，有助於觀察古代東西方植物、文化交流的多層關係。

Alfalfa, or more precisely, Medicago sativa, was introduced from Xiyu to China during the Han Dynasty by Zhang Qian as chronicled in Records of the Grand Historian and from Persia to ancient Greece around the sixth century BCE. This paper aims to explain if the forage λωτὸν in Iliad Book 2: 775-777 ＂ἵπποι δὲ παρ᾽ ἅρμασιν οἷσιν ἕκαστος λωτὸν ἐρεπτόμενοι ἐλεόθρεπτόν τε σέλινον ἕστασαν＂ is the same as alfalfa. Four approaches in this paper include: first, to sort out the likely referents for λωτὸν by casting light on the horse forage in the ancient Greek contexts; second, to better understand the historical background and cultural connotations of Medicago sativa in diverse Chinese literatures; third, to trace the tradition and innovation about the image of alfalfa in Chinese culture; fourth, to give a more comprehensive perspective to explore how the plants such as Medicago sativa can bear testimony to the process of the interaction between the East and the West. We can conclude from all these related pieces of information that what Achilles' horses consume on the Trojan plain may be other species instead of Medicago sativa; however, the introduction of Medicago sativa-westward to the Mediterranean area and eastward to China-can best showcase the existence and vitality of the East-West contact in ancient times.