Gentianales is an order of flowering plants, included within the asterid clade of eudicots. It comprises more than 16,000 species in about 1,138 genera in 5 families. More than 80% of the species belong to the Rubiaceae family.
Family: Apocynaceae (Dogbane Family)
Apocynaceae is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly called the dogbane family. Many species are tall trees found in tropical rainforests, but some grow in tropical dry (xeric) environments. Also perennial herbs from temperate zones occur. Many of these plants have milky latex, and many species are poisonous if ingested. Wikipedia.
Family: Rubiaceae (Coffee Family)
The Rubiaceae are a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules. The family contains about 13,500 species in 611 genera, which makes it the fourth-largest angiosperm family. Wikipedia