Structure foundation and ecological adaptability of Alternathera philoxeroides in heterogeneous habitats.
The morphogenesis and anatomical changes of Alternathera philoxeroides in different habitats (xeric and aquatic environments), were chosen as characteristics to appraise this weed under heterogeneous habitats. There were significant differences between the vegetative organs from two ecotype due to adaptation to heterogeneous ecotypes. The distribution and quantity of stomata between the two leaves showed a notable distinction; leaves of the xeric form had long epidermal hairs on both upper and lower epidermis, while the aquatic form had none on either. There were also significant differences as to type, quantity and proportion of conducting tissue in stems from different habitats and different ecobiomorphisms. The perennial roots from the xeric's stolon and rhizome had many adventitious buds which contained a high content of stored substances, and had the material and structural basis to be independent diasporas. In contrast, the aquatic only had numerous fibrous roots to meet absorption needs. The pollens of A. philoxeroides had a high abortion percentage (approximately 80%), which may be one reason for its low seed setting rate, but how it achieves invasion over long distances with such a low sexual reproduction rate deserves to be discussed, because of its significance in weed control.