What characteristic is typical of Milkweeds in the Asclepidaceae family?

Milkweeds, belonging to the Asclepiadaceae family, are known for their distinct milky sap, which is a defining characteristic of the genus Asclepias. This milky latex is produced as a defense mechanism against herbivores, deterring them due to its toxic and unpalatable nature. The presence of this sap plays a crucial role in the plant's ecology, particularly in its interactions with certain insects, such as monarch butterflies, which have adapted to feed on milkweed despite its toxicity.

The other options do not accurately represent typical characteristics of milkweeds. For instance, while some plants may have fuzzy leaves or spiny flowers, this is not a generalized attribute of milkweeds. Similarly, while milkweeds do produce clusters of tuber-like flowers, this is not the most defining feature compared to the significant milky sap. Whorled leaf arrangements can be found in various plant species, but milkweeds commonly exhibit alternate leaf arrangements. Thus, the notable characteristic of milky sap sets milkweeds apart within their family.