Final answer:
Charales can survive a dry spell due to their waxy cuticle, which prevents water loss. Sunken stomata also help conserve water by minimizing transpiration during dry conditions. Vascular tissue like xylem is not a feature of Charales.
Step-by-step explanation:
The characteristic of Charales that would enable them to survive a dry spell is a waxy cuticle. The cuticle is a waxy, waterproof layer that coats the aerial parts of the plant and plays a crucial role in preventing water loss from the plant's surface. Additionally, Charales have structural adaptations, such as sunken stomata, which are pores that can close to minimize transpiration, further aiding in water conservation during periods of limited moisture availability. Although Charales are known to be ancestral to land plants, they lack vascular tissue like xylem and therefore cannot transport water internally as efficiently as more evolved plants.