1 | Plants leafy |
1' | Plants lacking normally developed leaves |
2 | Plants densely white to golden or brown stellate-hairy, especially on the young parts |
2' | Plants glabrous or nearly so |
3 | Flowers minute (mostly less than 0.5 mm long); anthers 3, fused into a single unit; fruits up to 3 mm long; [in Malesia plants mostly less than 20 cm long; internodes in most species flattened in the one plane to form a cladode] |
3' | Flowers small (mostly 0.5-2 mm long); anthers 3 or 4, free from each other; fruits more than 3 mm long; [in Malesia plants mostly reaching more than 30 cm length; internodes in most species terete or when angular or flattened with the succeeding ones at right angles] |
4 | Inflorescence a single 3- or 5-flowered cyme, sometimes with subsidiary cymes or flowers arising within or below the first; anthers opening by several pores; tepals not persistent on the fruit (except in V. loranthi) |
4' | Inflorescence a spike of decussate single flowers or 3-flowered cymes; anthers opening by slits; tepals persistent on the fruit |