Hoya Identifier

How to use it

Start with the traits you are most sure of. Leaf shape and texture are a good place to begin, because they are what floras and original descriptions record most often. Choose one or more values in any group. Within a group, the values are alternatives: ticking “obovate” and “elliptic” finds species recorded with either shape. Across groups, every group you use has to match, so adding “climbing” to a shape search removes the species recorded only as trailing.

Measure a typical mature leaf, not the smallest new one or an unusually large one, and use the leaf-length groups: up to 5 cm, 5–10 cm, 10–20 cm and over 20 cm. The boundaries are inclusive, as the labels read: a leaf of exactly 5 cm counts in both “up to 5 cm” and “5–10 cm”, exactly 10 cm in both “5–10 cm” and “10–20 cm”, and exactly 20 cm in “10–20 cm” only. A species appears in every group its published leaf range touches.

The results update as you choose, in up to three lists:

1. Matches: species recorded with every trait you selected.
2. Not ruled out: species for which nothing you selected is contradicted, but at least one selected trait is not recorded in the sources. Each entry names the missing trait. These are weaker candidates, not matches.
3. Near matches: when you select traits in two or more groups, species that differ in exactly one of them. A single trait is easily misjudged, and leaves on the same species can differ: in a study of wild Hoya carnosa, leaf thickness varied between plants, and the authors attribute the differences to adaptation to sun or shade ^[3].

You can copy the address bar to share a search: the selected traits are stored in the link. That also means the traits travel with the address when it is opened, as described on the page and in the privacy policy.

How the data was compiled

Every species in the tool has a profile on this site, and the tool reads the same record. Names and native ranges come from the World Checklist of Vascular Plants, the Kew dataset that also powers Plants of the World Online ^[1]. Leaf and flower traits come from the descriptions cited on each profile: floras, original species descriptions and papers, supplemented by botanic garden and extension pages for cultivated plants. A trait is recorded only when a cited source supports it, and leaf-length groups are calculated from the cited measurements, not estimated.

That rule has a cost. Some species have no published leaf size or flower colour in any source we could open, so the tool treats those traits as unknown rather than guessing. An unknown trait never removes a species from the results, but it is shown next to the name so you know the match is weaker.

What it cannot do

The genus contains several hundred species ^[2], and this database covers a small, growing part of it, starting with plants that are common in cultivation. If your plant is not among them, the closest match will still be wrong. Many plants in the trade are hybrids or carry names that differ from the accepted botanical name; NC State notes that many species also have variegated cultivars ^[2], and variegation can change how a leaf looks. Leaf shape varies within a species, and young plants often have leaves that differ from mature ones.

Treat the results as a shortlist. Read the look-alikes section on each candidate profile, compare the flowers if your plant blooms, and check the native range and synonyms if your plant came with a label. For a confident identification of a difficult plant, flowers and specialist help are needed.