A genus of 200-300 species, hoya was earlier placed in the milkweed family. According to current taxonomy, this genus is placed under the dogbane family. There are several varieties that produce beautiful, vibrant-colored flowers. Buzzle provides information about some hoya plant varieties.

A study conducted at the University of Georgia revealed that Hoya carnosa, which is the most popular species of hoya, has the ability to remove pollutants from the indoor environment.The genus Hoya was named by Robert Brown, a Scottish botanist and palaeobotanist who is well-known for his contributions to the field of botany, especially plant taxonomy. This genus comprises more than 200 species of tropical plants. Several species belonging to this genus produce beautiful, sweet-scented flowers that appear in clusters. Though many species are twining vines, some might grow as shrubs. Some of the species can be epiphytes. Epiphytes should not be mistaken for parasitic plants. Though epiphytes grow on other plants, they get nutrients and moisture from air and rain. There are some species that start as terrestrials but turn into epiphytes later.

Hoya plants are also referred to as wax plants, wax flowers, or wax vines due to their waxy foliage and porcelain-like blooms. When cut, clear or milky sap oozes out. While gardening enthusiasts might marvel at the variety of blooms that the different varieties or cultivars offer, some of the varieties also produce ornate leaves. For instance, Hoya kerrii, which is called the Sweetheart Plant or Sweetheart Hoya, is popular due to its heart-shaped leaves.Hoya Plant Information✦ Plant Type: Evergreen perennial
✦ Growth Habit: Vine (climbing, trailing), shrubs
✦ Other Names: Wax plant, wax flower
✦ Native to: India, China, Thailand, Malaysia, Indonesia, Philippines, Polynesia, New Guinea, and Australia
✦ USDA Hardiness Zone: 10-12
✦ Light Requirement: Sun in the morning hours and bright, indirect light for the rest of the day
✦ Watering: Average; avoid excessive watering✦ Soil: Well-drained soil; Alkaline/neutral/acidic
✦ Flowers: Star-shaped flowers that grow in clusters
✦ Flowering Season: Throughout the summer
✦ Colors: White, pink, cream, yellow, orange, etc.
✦ Foliage Color: Green
✦ Other Characteristics: Some species might be toxic to livestockInformation About Popular Hoya VarietiesIf you are planning to grow this plant in your garden, you can select a variety, depending on the color of the blooms or the growth habit. The ones with a twining or trailing habit can be grown in hanging baskets.Hoya carnosaVery popular among gardening enthusiasts, Hoya carnosa has thick, glossy leaves that are about 6-10 cm in length and 4-6 cm in width. The plant can grow up to a height of 15 feet. Its popularity is often attributed to its sweet fragrance. Each umbrel has about 20-30 flowers.There is a red ring in the middle of the bloom, while the corona is white. The color of the corolla is white or light pink. The leaves are often green with some flecks. New leaves might have a reddish tinge, but will turn green as they mature. If you keep this hoya variety in a window facing north, you'll get a beautiful plant with bigger and darker leaves, but if you are more interested in its flowers, you need to place it in a window with more light.Hoya 'Indian Rope'Also called Hoya carnosa 'Krinkle Kurl', this plant can survive outdoors in USDA hardiness zones 10B through 11. It produces whitish-pink, star-shaped flowers during spring and summer. The curled leaves of the plant are also good to look at. It must be noted that this plant requires bright, indirect light. Water the plant, ensuring that the soil doesn't become too dry. It has a twining habit, and can grow up to a height of 4-6 feet.Hoya BellaHoya Bella has creamy white, star-shaped flowers, with purple at the center. The leaves could be dark/bright green or variegated cream and green. This variety has a twining habit. It will produce blooms throughout the summer, if it gets bright, indirect sunlight. It also requires a slightly humid environment. This miniature species is ideal for hanging baskets. It is quite popular with collectors.Hoya bilobataHoya bilobata is well-suited for trellis or hanging baskets. This plant produces small, glabrous leaves. It produces small flowers. The flowers have a faint scent.Hoya multifloraAlso referred to as the 'Shooting star' hoya, this species produces clusters of star-shaped white and yellow flowers that bend backwards. The leaves are dark green in color and are large, thick, and waxy. This plant grows well indoors.Hoya kerriiHeart or Valentine hoya is native to China and Thailand. The plant has succulent leaves. The veins are not visible on the heart-shaped leaves, as they are very thick and fleshy. It has a twining habit and would be perfect for a trellis.Hoya australisNative to Australia, this species produces waxy, white-colored flowers that give off a chocolate/vanilla fragrance. The leaves are large and oval in shape. While the new leaves are red in color, their color changes to green as they mature. Some of the subspecies require bright light, while some can thrive in part shade.Pictures of Hoya FlowersThough the aforementioned varieties are quite popular, you don't need to restrict yourself to the same. There are several species to choose from.On a concluding note, gardening enthusiasts can easily find a Hoya variety that produces ornate leaves and vibrant-colored flowers that are fragrant. All you need to do is provide the plant bright, indirect light and fulfill other requirements pertaining to the soil type and quality, fertilizer, watering, etc.