Coarse perennial herbs with leafy shoots 1.5-2m tall. Grows from large branching rhizomes (tuberous shoots) of up to 3.5cm in diameter. Rhizomes are internally pale and fragrant (Wagner et al., 1999, in PIER, 2002). Rhizomes grow vertical stems, grow up to 10cm long and form rhisome beds of up to a metre thick (Mather, Environment B.O.P). Leaves are oblong to lanceolate, 20-45 (-60)cm long, 5-10 (-12.5)cm wide, upper surface glabrous, lower surface sparsely pubescent, apex acuminate, sessile, ligules membranous, (1-) 2-4cm long, entire, pubescent, sheaths glabrous. Flowers fragrant, inflorescences erect, basically ovoid, 15-20cm long, ca. 8cm wide, primary bracts green, membranous along margins, loosely imbricate, broadly ovate to elliptic, 5-8cm long, ca. 3.5cm wide, apex usually obtuse, pubescent to glabrate, rachis permanently concealed, cincinni usually 4-flowered, calyx cylindrical, 4-5cm long, pubescent or rarely glabrate; corolla yellow, the tube slender, 8-9cm long, the lobes linear to linear-lanceolate, 4-5cm long; labellum often centrally flushed with dark yellow, broadly obovate, about as long as staminodes, (2.5-) 3-4cm wide, the base tapered into a claw; stamen yellow, about as long as labellum or slightly longer; lateral staminodes white, spatulate to lanceolate, (2.5-) 4-6cm long. Capsules unknown (Wagner et al., 1999, in PIER, 2002)

Flowers produce a powerful spicy citrus scent (KobaKoba 2001).

Medicinal purposes (Brach, Flora of China).

Yellow ginger occurs in rainforests, moist forests, along roadsides, in open habitats and along streamsides (PIER, 2002). In India it is found at altitudes of between 1200 metres and 2000 metres (KobaKoba 2001).

Spreads outwards along the ground by way of rhizomes, with new stems sprouting annually (Environment B.O.P).

Cultivated in New Zealand gardens since 1865. (Mather, Environment BOP)

This species is a major invader of native forests in Hawaii (Carr, University of Hawaii), New Zealand, and La Réunion (PIER, 2002). In New Zealand yellow ginger ( H. flavescens) exhibits dense rhizomal growth which aids its spread and dispersal and prevents the growth of native plants. There is concern that it may permanently displace uncommon plants or specialised plant communities in this country (NZ DOC).

Physical: Plants may be dug out. All seedlings must be removed to prevent regeneration. Stalks and roots are difficult to burn and should not be composted. Even small root fragments will resprout.

Chemical: Treat with herbicide. Escort 25 gm/100 l water + 0.1% Pulse; Roundup 2% + 0.2% Pulse and Amitrole. If in doubt, use concentrations as recommended by the manufacturer. Apply from spring to late autumn. Spray lightly on the leaves and roots. Do not remove the leaves or stalks until they have gone brown and dried out. This will take three to four months. During spraying, non-target plants can be shielded with cardboard or plastic sheets. The use of a marker dye helps to avoid double spraying and wastage, and a foaming agent can be added to the spray to prevent drift.
For larger plants, the cut stump method can be used. Cut the base of the plant close to the ground with a straight flat cut. The cut must be horizontal so the herbicide will stay on the cut area and be absorbed. Apply the herbicide as instructed on the label to the stems and roots. Apply immediately, as the sap ceases to flow once the tissues are severed. There are several convenient ways the application can be made, with a paintbrush, eye dropper or a small squeeze bottle. This method uses less spray and reduces the risk to non-target plants. Make sure you leave the plants in the ground until the roots have died off.
Another approach is to cut and remove all stalks and leaves and rake away ground litter to expose the roots. The roots should then be sprayed, covered with leaves, and left. Don't use this method after the flowering heads have formed seeds. The spray will have noticeable effects in three months, but the plant will take 12 to 15 months to fully die and rot. With all spraying make sure to read the instructions on the manufacturer's label closely and always wear protective clothing (NZ Department Of Conservation).