Lactuca "chiangdaoensis"

Primary tabs

Lactuca "chiangdaoensis"

no image available

Description

Rhizomes thick, c. 1.5 cm in diam. 5 to 8 cm long. Stem of lower half procumbent, branched 3 to 5 times, of upper half erect, branched again 3 to 5 times. Basal leaves withering at flowering; cauline leaves petiolate, lamina cordate to kidney-shaped, 4–5 × 4–6 cm, apex obtuse or rounded, base narrowly or broadly cordate, margin entire, mucronate, upper surface nearly glabrous, lower surface densely pubescent, especially on veins, hairs brownish, petioles 3–7 cm long; upper cauline leaves grdually smaller, lamina triangular, petiole shorter. Synflorescence of a solitary capitulum, peduncles 3–6 cm long. Capitula c. 3 cm in diam. at flowering; involucre tubular, c. 13 mm long and 4 mm in diam.; phyllaries 3–4-seriate, imbricate; outermost phyllaries triangular 2 × 2 mm; inner phylaries 8, uniseriate, lanceolate c. 2 mm wide, margin white membranaceous, apex obtuse. Receptacle areolate. Florets 12–14, ligules blue, angular-ovate, 20–22 mm long, c. 4 mm wide, tune c. 4 mm long, pubescent; anther rube c. 2.5 mm long; style arms c. 2.3 mm long. Achenes (only known immature) fusiform (?) with short beak. Pappus c. 6 mm long; inner bristoles capillary, white; outer minute row of bristles c. 0.25 mm long, ± brownish.
Somewhat modified from Koyama & al. 2016: 241.A

Image sources

Koyama & al. 2016: 242, fig. 32 (flowering branch, capitulum)B

Distribution

Asia-Tropical: ThailandnativeC,D

Bibliography

A. Koyama H. & al., Flora of Thailand 13(2) Compositae. 2016 (as Cicerbita chiangdaoensis H. Koyama)
B. Koyama H. & al., Flora of Thailand 13(2) Compositae. 2016 (as Cicerbita chiangdaoensis H. Koyama)
C. Koyama H. & al., Flora of Thailand 13(2) Compositae. 2016 (as Cicerbita chiangdaoensis H. Koyama)
D. Koyama H., Taxonomic Studies in the Compositae of Thailand 13. Tribe Lactuceae in Bulletin of the National Science Museum, Tokyo. Series B, Botany 27(4): 133-148. 2001 (as Cicerbita chiangdaoensis H. Koyama)