Description from Flora of China
Gaertnera hongkongensis Seemann; Ixora crocata Lindley; I. stricta Roxburgh; I. stricta var. incarnata Bentham; Pavetta kroneana Miquel; Sykesia hongkongensis (Seemann) Kuntze; Tsiangia hongkongensis (Seemann) But, H. H. Hsue & P. T. Li.
Shrubs, 0.8-2 m tall; branches glabrous. Leaves opposite, sometimes apparently in whorls of 4 due to reduced stem internodes, sessile or petiolate; petiole to 5 mm, glabrous; blade drying leathery, oblanceolate, oblong-oblanceolate, obovate, elliptic-oblong, or lanceolate, 6-18 × 3-6 cm, glabrous on both surfaces, base cuneate to shortly truncate or rounded, apex obtuse or rounded to acute; secondary veins 7-9 pairs; stipules persistent, united around stem to almost interpetiolar, triangular to broadly triangular, 3-7 mm, glabrous to glabrescent, costate, acute and with arista 2-10 mm. Inflorescence terminal, congested-cymose to congested-corymbiform, many flowered, puberulent to hirtellous, subsessile to pedunculate; peduncle to 1.5 cm, often subtended by 2 reduced leaves or leaflike bracts; branched portion 1-4 × 1-5 cm (not including corollas); bracts triangular, 0.2-1 mm; pedicels to 2 mm. Flowers subsessile to pedicellate. Calyx glabrous; hypanthium obconic to ovoid, 1-1.5 mm; limb deeply lobed; lobes triangular to ligulate, 0.5-1 mm, acute or obtuse. Corolla red or reddish yellow, outside glabrous; tube 20-30 mm, glabrous in throat; lobes ovate, elliptic, or broadly elliptic, 5-7 × 4-5 mm, broadly obtuse to rounded. Drupe reddish black, subglobose and shallowly didymous, 6-7 × 6-7 mm, glabrous. Fl. May-Jul and Dec, fr. Sep-Oct.
This is a commonly collected species of Ixora in China, apparently growing naturally as well as in cultivation. The occasional short stem internodes, which sometimes produce congested groups of leaves, appear to possibly be due to a change in growth pattern at the top of a seasonal spurt that includes several internodes. The circumscription and characters of this species were considered in some detail by Fosberg and Sachet (Baileya 23(2): 77. 1989), who noted that it is sometimes cultivated. Bridson (Kew Bull. 55: 1011-1012. 2000) studied the identity of Tsiangia, and formally synonymized its only species, T. hongkongensis, with I. chinensis.
Thickets, sparse forests; 200-800 m. Fujian, Guangdong, Guangxi [Indonesia, Malaysia, Philippines, Vietnam; widely cultivated in tropical regions].