Sunflowers in the Pangeacene
Sunflowers were one of the first plants on Serina to produce tree-like growth forms and are today Serina's most successful trees, though not the only plants to grow in this manner (clover, grasses, and formerly bamboo have at different times also adopted upright woody trunks that allowed them to reach great heights.) Certain members of this family adopted the symbiotic relationship with ants originally forged by extinct bamboos and have now been evolving closely into a symbiotic relationship with them for over one hundred and fifty million years. One of the earliest benefits this carried, after protection, was that trees no longer had to advertise their flowers to pollinators. When they are already covered in swarms of insects, colorful petals became unnecessary, and have been lost from all but the most primitive surviving lineages. The once large, colorful flowers of the sunflower were energetically expensive to produce, and as they are no longer needed have reduced over the eons to small clusters of insignificant sepals and stamens growing along the stems, hidden by the foliage. Instead of nectar, they simply sacrifice a small percentage of pollen to their ant pollinators as a food source, relying on the fact that some will become stuck to the ants' bodies and be taken to the next flower they visit.
A more recent step taken by the most advanced members of sunflower tree clade has been the production of living seedlings, rather than seeds, directly on the parent plant. These seedlings are often protected by bitter resins or irritating hairs that make them unappealing to herbivores, and except for certain exceptions such as the chimera tree most lack an energy-rich store of food to appeal to seed-eaters, as the seedling is attached to the parent until it is shed and is adapted to start growth immediately on landing. This may be a direct response to predation by seed-smashing molodonts, as due to the specialized crushing jaws of these animals they are likely to damage even seeds that they intend to store for later to the point that germination is prevented, meaning that they are less efficient seed dispersers than the birds which formerly filled this niche. While the chimera tree is an extreme example in utilizing flying ants to disperse its offspring other forms have developed wing-shaped appendages of their own that spin when the plantlet drops off the mother tree, carrying it some distance away in a good breeze. When the seedling lands somewhere suitable it puts down roots and can commence growth instantly. Like any adaptation, however, there are negatives and positives to each system. Though these seedlings are more resistant to predation, they are unable to survive in poor growing conditions for any length of time as a dormant seed can. If a living seedling drops somewhere less than suitable for its growth, it stands much less chance of being blown or washed away to somewhere better than a comparable seed in the brief window before it runs out of water or energy.