Question: Which is of a genus of tropical evergreen perennials or subshrubs, Ceropegia or Centradenia?

Context paragraphs:
Musa ornata: Musa ornata (flowering banana) is one of more than 50 species of banana in the genus "Musa" of the family Musaceae.  Most of these species are large tropical evergreen perennials, mainly from lowland areas with high temperature and humidity.  "Musa ornata" originated in southeast Asia, and is cultivated for its commercial and ornamental value.  The fruit is attractive but tends to be inedible.

Centradenia: Centradenia is a genus of 4-5 species of tropical evergreen perennials or subshrubs, native to Central America and Mexico.

Iberis: Iberis , commonly called candytuft, is a genus of flowering plants belonging to the family Brassicaceae.  It comprises annuals, evergreen perennials and subshrubs native to the Old World.  The name "candytuft" is not related to candy, but derives from "Candia", the former name of Iraklion on the Island of Crete.

Ceropegia stapeliiformis: Ceropegia stapeliiformis is a flowering plant in the genus "Ceropegia" (Apocynaceae), native to South Africa and Swaziland.  Common names include Serpent Ceropegia, Snake creeper, and Slangkambro.

Ceropegia woodii: Ceropegia woodii is a flowering plant in the genus "Ceropegia" (Apocynaceae), native to South Africa, Swaziland, and Zimbabwe.  It is sometimes treated as a subspecies of the related "Ceropegia linearis", as "C. linearis" subsp.  "woodii".  Common names include chain of hearts, collar of hearts, string of hearts, rosary vine, hearts-on-a-string and sweetheart vine.

Gnetum: Gnetum is a genus of gymnosperms, the sole genus in the family Gnetaceae and order Gnetales.  They are tropical evergreen trees, shrubs and lianas. Unlike other gymnosperms, they possess vessel elements in the xylem.  Some species have been proposed to have been the first plants to be insect-pollinated as their fossils occur in association with extinct pollinating scorpionflies.  Molecular phylogenies based on nuclear and plastid sequences from most of the species indicate hybridization among some of the Southeast Asian species.  Fossil-calibrated molecular-clocks suggest that the "Gnetum" lineages now found in Africa, South America and Southeast Asia are the result of ancient long-distance dispersal across seawater.

Ixora: Ixora is a genus of flowering plants in the Rubiaceae family.  It is the only genus in the tribe Ixoreae.  It consists of tropical evergreen trees and shrubs and holds around 545 species.  Though native to the tropical and subtropical areas throughout the world, its centre of diversity is in Tropical Asia.  "Ixora" also grows commonly in subtropical climates in the United States, such as Florida where it is commonly known as "West Indian Jasmine".  Other common names include "viruchi", "rangan", "kheme", "ponna", "chann tanea", "techi", "pan", "siantan", "jarum-jarum/jejarum", "jungle flame", "jungle geranium" among others.  The plants possess leathery leaves, ranging from 3 to 6 inches in length, and produce large clusters of tiny flowers in the summer.  Members of Ixora prefer acidic soil, and are suitable choices for bonsai.  It is also a popular choice for hedges in parts of South East Asia.  In tropical climates they flower year round and are commonly used in Hindu worship, as well as in ayurveda and Indian folk medicine.

Ceropegia: Ceropegia is a genus of plants within the family Apocynaceae, native to Africa, southern Asia, and Australia.  It was named by Carl Linnaeus, who first described this genus in volume 1 of his "Species plantarum", which appeared in 1753.  Linnaeus thought that the flowers looked like a fountain of wax.  From this the scientific name was derived: ‘"keros"’ meaning wax and ‘"pege"’ meaning fountain (Pooley, 1998).  They have many common names including lantern flower, parasol flower, parachute flower, bushman’s pipe, string of hearts, snake creeper, wine-glass vine, rosary vine, and necklace vine.

Ctenanthe: Ctenanthe is a genus of flowering plants of the family Marantaceae described as a genus in 1884.  They are evergreen perennials, native to Central and South America (primarily Brazil).  They are grown for their attractive, often variegated foliage.  They are frost tender, requiring a minimum temperature of 13 C .

Pachysandra: Pachysandra is a genus of five species of evergreen perennials or subshrubs, belonging to the boxwood family Buxaceae.  The species are native to eastern Asia and southeast North America, some reaching a height of 20 - , with only weakly woody stems.  The leaves are alternate, leathery, with an entirely too coarsely toothed margin, and are typically 5 - long.  The small uni-sexual blooms are greenish-white and produced in late spring or early summer.

Supporting paragraphs: Ceropegia Centradenia
Answer: Centradenia