When studying a concept as broad as Greco-Macedonian imperialism in the East, a fruitful method is to take an aspect of empire and explore its history during the Achaemenid period and then its use by the Greeks and Macedonians. Therefore, I propose to examine the relationship these imperial powers had with plants, which are commonly used as a tool of colonial imperialism, especially when transported from one area of an empire to another (Brockway 1983). This practice allows rulers to express the extent and productivity of their domain as well as their control over the natural world. In this way, their use of plants provides a window into the failure of the Seleucids to firmly cement their empire.
In early Greek ethnographies, plants form a part of the overall narrative of exoticism (for example, Ctesias fr. Lenfant  F45.36 on a lac-producing tree), and they express differences between center and periphery (for example, Herodotus 3.106 and 4.40). The τÏŒπος of the lush, exotic East is continued even in the works of Megasthenes, who lived in India (Murray 1972 and Kartunnen 1989). On the other hand, botanical literature from the same time period (Theophrastus) presents a less utopian picture of India.
Further, the metaphor provided by plants was put to use by eastern monarchs. In the Achaemenid period, the gardens (παρÎ¬δειδοι) of the Persian kings can be considered “microcosms of empire” (Kuhrt 2007), in which even vegetation is shown to be under imperial control. This practice is continued in the Seleucid period, when attempts to introduce plants to and from their new territories either succeed (Strabo 15.3.11 on the introduction of grapevines to Susis) or fail (Pliny NH 16.59.135 on the failure to import cardamom to Babylon). Additionally, plant products were used as luxury items and as temple dedications (OGIS 214 on an offering of Seleucus I to the temple of Apollo at Didyma). Thus, the transport of live plants and of plant products is a large-scale analogy for the failures and successes of Greco-Macedonian imperialism in the East.
A case study for these interactions is provided by the garden of Harpalus, whose flight has been understood as a consequence of the breakdown in command during Alexander’s absence in India (Badian 1961 and Blackwell 1999), and whose gardening endeavors shed light on relations between the Greco-Macedonians and the colonial empire they inherited. Both Plutarch (Vit. Alex. 38.5) and Theophrastus (Hist. Plant. 4.4.1) relate the story, with special emphasis on his failure to grow ivy. This provides a close look at one particular plant that had strong resonances with imperial power (Hist. Plant. 4.4.1 on Alexander’s crown of ivy in India and II Macc.6:7 on Antiochus IV’s imposition of ivy wreaths on the Jews), and shows how ivy can be used to express both the power and the “Greekness” of an individual.
From all of these interactions with plants, some clear conclusions arise. First, the lush, wild vegetation of the eastern regions of the Achaemenid and Seleucid empires, as portrayed in Greek ethnographic treatises, was put under control in the royal gardens and παρÎ¬δεισοι, which displayed the luxury and power of the kingship and emphasized the extent and fertility of the realm. Second, the ability to successfully cultivate plants was indicative of the ability to control an empire. The Achaemenids succeeded in growing foreign plants in Persepolis, but Seleucus I failed to introduce cardamom to Babylon and Harpalus was unsuccessful in planting ivy in the same city. Thus, the flight of Harpalus and the crumbling of Seleucus’ empire reflect their problems in the garden. Third, the success of the Achaemenids with the center-periphery model of hegemony was not replicated by the Seleucids: just as foreign plants would not grow in Babylon under the Seleucids, so too their empire did not take root.