A World with Fewer Flowers
Bright, colorful flowers of the types that humans would recognize have been much less abundant in general since the Thermocene-Pangeacene boundary brought many representative plant clades to extinction. Grasses still dominate most of Serina's drier regions, virtually all of which have insignificant wind-pollinated flowers. Many flowering trees in wetter climates have likewise exhibited a trend toward the shrinking of their flowers and consolidation of their parts into small clusters hidden close to their stems. Dandelions, which were already wind-dispersed, have given rise to many descendants that use the breeze to pollinate their flowers in the manner of the grasses and have subsequently lost their petals. It is so that since the start of the Pangeacene, Serina is a less colorful world.
Of the flamboyant blossoms you are still likely to see, most are very likely to originate from two clades - clovers, one the last more or less totally insect-pollinated plant groups in existence, which are most abundant in the form of low-growing prairie plants worldwide and as bushes and small trees in temperate climates, and an aberrant clade of grasses known as grandifloragrams (roughly translating to large-flowered grasses). Grandifloragrams, which include chokeweed and nanboo as their extant members, are a widespread family of specialized grasses which evolved in the Tempuscene and are notable for having large, colorful bracts surrounded their flowers, producing nectar to attract animal pollinators, and producing fleshy fruits or seed pods rather than loose seeds borne on stalks. Unlike all other grasses, plants of this ancient and diverse family rely on animals - not wind - to fertilize their flowers, and it is almost ironic that they are today one of only a few plant clades left which operate by this method of reproduction. Most recruit insects to do the job, but the large forest-forming representatives of the group known as nanboos - a group of grandiflorigrams allied by producing large psuedostems from underground rhizomes - rely almost entirely on birds and tribbets, with very large blossoms full of nectar.
Because there are fewer suitable flowers on Serina in the Pangeacene than before, there are fewer groups of specialist pollinating insects to service them. Ants are still major players, and since the extinction of the formerly diverse pollinating crickets, the florgusts, at the end of the Thermocene only one other group of insect has produced any specialist pollinator lineages. This would be the beetles, which have produced one clade of agile flyers with highly elongated proboscis that feed mainly on the nectar of nanboo, the only insects which can readily access it deep inside these plants' very large blossoms.
In the deserts of Serina in the Pangeacene things are a little different. Conditions are dry, and plants of a given species are often greatly spaced out, making wind pollination unreliable. Indeed, it was in this very type of environment that the first grandiflorigrams so long evolved in the Tempuscene, and many other plants here have similarly retained a dependence on animal pollinators and large blossoms to attract them. Sunflower trees such as the desert puddlebuds, for example retain small daisy-like blossoms, even though their woodland relatives have lost them, and leafless cactus-like species produce very large flowers after rainfall which attract not only insects but also birds and tribbats. Members of other groups that inhabit deserts such as dandelions also retain colorful flowers.