Rosids

Clade of Superrosids

Food, Plant source foods, Flowering plats (angiospermae), Mesangiosperms, Eudicots, Core eudicots, Superrosids

Availability: Earth

Note: For better understanding, please read the article on flowering plants (angiospermae) first. If you come across unfamiliar words, you can click on any highlighted term to open the glossary with definitions of key botanical terms.

Introduction

The rosids are a large group within flowering plants, including around 70,000 species—which accounts for more than a quarter of all known angiosperms. This clade stands out for its vast species richness and major role in plant evolution. Depending on the chosen classification system, rosids are arranged into 16 to 20 orders. These are further divided into approximately 140 families, showcasing an extensive variety of forms and ecological strategies.

Fossils attributed to rosids have been found in Cretaceous-age deposits. Molecular clock studies estimate that the group may have originated during the Aptian or Albian stages, between roughly 125 and 99.6 million years ago, a period marked by rapid floral diversification.

In present-day environments, rosid species are dominant in many forest ecosystems and drive much of the diversity in living plant lineages. Additionally, rosid herbs and shrubs form a significant portion of the temperate, alpine, and arctic floras, underscoring their wide environmental distribution.

Description of Rosids

There are no clear non-molecular distinctive traits that universally define the species grouped within the rosid clade. While many of these plants tend to exhibit perianths with unfused petals or sepals, and a stamen count exceeding that of the calyx or corolla, numerous exceptions exist.

A common feature among rosids is the presence of bitegmic and crassinucellate ovules. This trait marks a key distinction from the asterids, which typically have unitegmic and tenuinucellate ovules. This difference in ovule structure remains one of the few consistent morphological contrasts between these two major groups of flowering plants.

Classification of Rosids

This clade is further divided into 2 clades (which together would actually form the clade of eurosids, a classificatory step that in this context seemed superfluous to us) and one order:

Clades:

• Fabids (acorns, apples, apricots, beans, cherries, chestnuts, chickpeas, cucumbers, peas, peaches, pears, peanuts, lentils, melons, watermelons, soybeans, strawberries, zucchinis, pumpkins)
• Malvids (broccoli, cabbages, cashews, cloves, lemons, lychee, mangoes, mustard seeds, pistachios, radishes, rambutan)

Order:

• Vitales (grapes), an order that exclusively includes the family Vitaceae. Consequently, we will focus only on this family.