紫椿 zi chun

Swietenia sureni Blume, Catalogus, 72. 1823; Cedrela febrifuga Blume; C. febrifuga var. pealii C. Candolle; C. febrifuga var. verrucosa C. Candolle, p.p. (as to Forbes 118 and Forbes s.n. from Sumatra); C. microcarpa C. Candolle var. grandifoliola C. Candolle; C. sureni (Blume) Burkill; C. toona Roxburgh ex Rottler var. henryi C. Candolle; C. toona var. pilistila C. Candolle; C. toona var. warburgii C. Candolle; Surenus febrifuga (Blume) Kuntze; Toona ciliata M. Roemer var. candollei Bahadur; T. ciliata var. grandifoliola (C. Candolle) Bahadur; T. ciliata var. henryi (C. Candolle) Harms; T. febrifuga (Blume) M. Roemer.

Trees, medium sized to 40 m tall; trunk to 25 m tall, to 3 m d.b.h., with or without buttresses (to 2 m); crown fairly wide, spreading, occasionally dense. Bark whitish, grayish brown, gray, or light brown, usually vertically fissured and flaking; inner bark pinkish white, pinkish brown, reddish brown, or orange, fibrous; sap-wood white, pink, or pale red, sweetly aromatic when cut. Twigs pilose and often densely and prominently lenticellate with conspicuous verrucose lenticels. Leaves 29-84 cm; petiole 7-12 cm, pilose to glabrescent, often lenticellate; rachis moderately pilose to glabrescent, occasionally velutinous; leaflets usually 6-9(-12) pairs; petiolules (2-)4-12 mm, pilose/villous to glabrescent; leaflet blades lanceolate to ovate-lanceolate, 7-14(-19.5) × 3.1-6(-7) cm, often dark grayish brown, moderately pilose to glabrescent, usually with short trichomes and club-glands apically on midveins, veins basally pilose to villous/velutinous, base symmetrical to asymmetrical, margin entire, apex acuminate to occasionally acute. Inflorescences to 40 cm, pendent; rachis pilose to villous with medium to long spreading trichomes, occasionally glabrescent. Flowers 4-5 mm, sweetly aromatic. Pedicel (0.3-)0.7-1.3 mm, pilose to villous. Calyx 1-1.5 mm, outside pilose to glabrescent, lobes imbricate; sepals usually shallowly triangular especially in bud, 0.6-1 × 0.8-1.5 mm, outside villous to glabrescent, margins ciliate, apex usually acute. Petals white, creamy white, or pale pink, 3.5-5 × 1.6-3.2 mm, outside villous to glabrescent but in bud usually with conspicuous ciliate bands of long appressed trichomes on margins. Androgynophore 2.5-4.7 mm; filaments 1.2-2.5 mm (male flowers), 1-1.3 mm (female flowers), pilose to villous with scattered to dense long trichomes; anthers of male flowers 0.7-1.3 × 0.3-0.8 mm, apex usually apiculate; antherodes of female flowers sagittate, 0.5-0.9 × 0.2-0.6 mm. Disk orange to red, 1.2-2.5 mm in diam., densely pilose. Ovary 1.6-2.8 mm in diam., moderately to densely pilose, with to 6 ovules per locule; style 1.2-3 × 0.2-0.5 mm (male), 0.5-1 × ca. 0.3 mm (female), pilose with scattered usually appressed trichomes especially on basal half; stylehead 0.7-1.3 mm in diam. Capsule 1.4-2(-2.4) cm; columella 1.4-2(-2.4) × 0.5-0.8(-1) cm, concave with apical scarring; valves dark brown to blackish brown, rough, verrucose, with conspicuous and often ovoid 0.3-2 × 0.4-1.3 mm rusty lenticels. Seeds 1.1-2(-2.2) cm × (3-)4-4.8 mm, winged at both ends, wings unequal with broadly obtuse apices; seed body 5-8 × 1.5-2 mm. Fl. Apr, fr. Apr-May.

Open hillsides, occasional in ravines, forests, and woods; 700-1600 m. Guizhou, Hainan, Sichuan, Yunnan [Bhutan, India, Indonesia, Laos, Malaysia, Myanmar, Papua New Guinea, Thailand].

This species also yields excellent timber. Its bark is used as a powerful astringent and a purgative throughout its range. In Indo-China it is considered to be a tonic, an antiperiodic, and an antirheumatic, while in Indonesia it is used as an astringent and a tonic for treating diarrhea, dysentery, and other intestinal infections. The leaf extracts apparently have an antibiotic activity against Staphylococcus, with leaf tip con-coctions being applied to swellings. Because of the difficulty of separating this species from Toona ciliata in the herbarium, it is probable that T. sureni is more widespread in China than the above localities indicate.