Gen info
- Exallage is a genus of flowering plants in the family Rubiaceae. The genus is found from tropical and subtropical Asia to the southwestern Pacific.
- Hedyotis costata is a genus of flowering plants in the family Rubiaceae. It comprises about 115 species.
- Hedyotis, named by Linnaeus in 1753, derives from two Greek words: hedys meaning "sweet" and otos meaning "ear", referring to the sweet-scented ear-shaped leaves of some species. (3)
- An understudied plant.
- The Hedyotis-Oldenlandia complex is one of the most enigmatic groups in Rubiaceae due to a wide range of morphological diversity observed and long-standing taxonomic complexity with conflicting generic delimitations. (5)

Botany
• Hedyotis costata is a rather coarse, spreading, diffuse, villous herb 30 to 60 centimeters long. Leaves are petioled, elliptic-lanceolate, 5 to 11 centimeters long, and 1 to 3 centimeters wide. Cymes are villous, small, borne in the axils of the leaves, and furnished with short stalks under 1.5 centimeters long. Flowers are very small, white, and crowded in small heads. Fruit is a capsule, small, rounded and hairy.

• Herbs, annual or perennial, diffusely branched, weak to clambering or prostrate, to 60 cm tall; stems flattened, 4-angled, or subterete, sometimes sulcate, densely villous or hirsute with trichomes drying golden yellow. Leaves subsessile to petiolate; petiole 1-10 mm, densely hirtellous to villous; blade drying membranous to papery, lanceolate, elliptic-lanceolate, or elliptic, 2-8 × 0.5-3 cm, adaxially sparsely to densely strigose and/or strigillose to hirsute on lamina and moderately to densely pilosulous on principal veins, abaxially sparsely strigillose to glabrescent on lamina and densely strigose to hirsute on principal veins, base cuneate to obtuse and frequently decurrent, apex acute to usually acuminate; secondary veins 4-6 pairs; stipules fused to petiole bases, truncate to triangular, 2-4 mm, moderately to densely hirtellous, hirsute, or villous, with 3-5 linear or setose lobes 2-5 mm. Inflorescences axillary, congested-cymose, capitate, or fasciculate, 5-20 mm, densely hirtellous to hirsute, several to many flowered, pedunculate; peduncles 1-3 per leaf axil, 2-12 mm; bracts subulate, to 1 mm. Flowers sessile or subsessile, distylous. Calyx densely hirtellous to villosulous; hypanthium portion turbinate to obconic, ca. 0.5 mm; limb lobed nearly to base; lobes lanceolate to triangular, 0.3-1 mm. Corolla white or purple, tubular to funnelform, outside puberulent to pilosulous; tube 1.2-1.5 mm, pubescent in throat; lobes narrowly elliptic to triangular, 0.8-1.2 mm. Anthers 0.5-1 mm, exserted. Stigma 0.3-0.6 mm, exserted. Fruit indehiscent, subglobose, 0.8-1.5 mm in diam., pilosulous; seeds 6-8, black, trigonous. (Flora of China)

Distribution
- Native to the Philippines. (2) (4)
- In open grasslands and thickets at low altitudes in Rizal, Laguna, Camarines, and Sorsogon Provinces in Luzon; and in Culion, Busuanga, Palawan, and Mindanao.
- Also native to Assam, Bangladesh, Cambodia, East Himalaya, Jawa, Laos, Malaya, Myanmar, Nepal, New Guinea, Nicobar Is., Thailand, Vietnam. (2)

Parts used
Roots.

Uses
Folkloric
- Roots boiled and made into a lotion for rheumatism.
- In Chinese medicine, used for malaria, hepatitis, rheumatism, conjunctivitis. The plant is an ingredient in a polyherbal formulation for atrophic rhinitis. (1)

Studies
• Herbal Mixture for Atrophic Rhinitis: Invention relates to a traditional Chinese medicine for the treatment of atrophic rhinitis prepared from a mixture of medicinal materials viz., folium eucalypti, sophora fruit, wrinkled giant hyssop herb, saffron crocus, fortune firethorn, athelenota ananas and Hedyotis costata. (1)

Availability
Wild-crafted.

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