Description from Flora of China
Calla occulta Loureiro, Fl. Cochinch. 2: 532. 1790; Spirospatha occulta (Loureiro) Rafinesque; Zantedeschia occulta (Loureiro) Sprengel.
Rhizome creeping; terminal part of stem erect, 30-50 cm tall; cataphylls and prophylls linear-lanceolate, 15-16 × ca. 2.5 cm. Petiole 25-40 cm, proximal part with 2-5 mm wide sheath; leaf blade sagittate-cordate, 15-30 × (8-)15-28 cm or usually more; primary veins 7 per side, 2-4 of these basal, downward to basal lobes and then arching into leaf margin, secondary and tertiary ones thinner, numerous. Inflorescences 1-3 together; peduncle shorter than petioles, 10-15 cm. Spathe pale green, oblong or elliptic, 5-6.5 × 3-3.2 cm, fusiform before anthesis, distal part slightly spreading and shortly boat-shaped at anthesis, 5-6 cm wide when spread out completely, apex with a beak ca. 1 cm. Spadix sessile or shortly stipitate, 3-5 cm; female zone 1-1.5 cm × 4-5 mm; ovary oblong, 3-loculed, with 1 staminode at side of base; ovules numerous; placentation axile; stigma disciform; male zone 2-3 cm × 3-4 mm. Seeds brown, oblong. Fl. Jul-Sep.
One of us (Boyce) notes that the correct application of the name Homalomena occulta is obscure. The type (that almost certainly came from Huế in Vietnam) is lost, and the material that Schott annotated as being H. occulta consists of at least three species. The above description appears to be based on at least two species.
The aromatic rhizomes are used medicinally to treat traumatic injuries, fractures, stomach aches, lumbago, intestinal parasites, and rheumatic arthralgia.
Dense valley forests, bamboo forests, mountain shrub forests; below 100-1100 m. Guangdong, Guangxi, Hainan, Yunnan [Laos, Thailand, Vietnam].