Lilium medogense
S. Yun Liang (1985)
(Mòtuō Bǎihé / 墨脱百合 – “Mêdog Lily”)
Overview
Section: Sinomartagon (Asiatic section)
Origin: Southeastern Xizang (Tibet Autonomous Region, China) – Mêdog Xian (墨脱县)
Habitat: Rocky clearings in Abies forests at ca. 3 000 m (≈10 000 ft)
Type: Small to medium-sized herbaceous lily; yellow, nodding, bell-shaped flowers
Status: Endemic and rare; known from a single region in southeastern Tibet
Description
(After Liang 1985; Flora of China Vol. 24 p. 138; field notes by Yijia Wang 2023)
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Bulb subglobose, ~2.2 cm diam.; scales purple-red in the type description (Flora of China) but reported white in situ during the 2023 rediscovery. The discrepancy may reflect photo-oxidation of pigments upon exposure to UV light.
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Stem 35–50 cm, finely papillose.
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Leaves 5–8 in whorls plus scattered alternate leaves; blades obovate-oblanceolate or elliptic, 4.5–6 × 1.7–2.2 cm.
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Flowers 1–3, campanulate, nodding, borne in June. Tepals yellow, dark purple at base adaxially, unspotted, elliptic (5–6 × 2–2.4 cm), smooth.
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Stamens much shorter than tepals; filaments ~2.5 cm, glabrous; anthers oblong (~1.3 × 0.2 cm).
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Ovary ~1.4 × 0.3 cm; style ~2.5 cm; stigma capitate (~8 mm diam.).
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Flowering season – June; fruits – late summer (likely August–September).
Ecology and Habitat
Lilium medogense grows in rocky openings within montane fir (Abies) forests, at elevations around 3 000 m. The rediscovery photographs show residual snow patches even in late June, confirming an extremely short growing season (June–August) before frost returns in early September.
The combination of high humidity, strong UV light, and brief summer warmth suggests a tightly compressed phenological cycle—rapid emergence, flowering, and senescence within 8–10 weeks.
Rediscovery (Yijia Wang, 2023)
The species was long known only from the 1985 type description until it was rediscovered by nurseryman Yijia Wang near the Tibetan border in Mêdog County.
Wang’s photos confirm all diagnostic features—whorled leaves, nodding yellow flowers, and dark basal throat—matching the Flora of China description exactly except for the bulb color.
“The snow you see in the background is on the south-facing slope. It usually melts by June and returns again in September. The growing season for L. medogense is only about two months.” — Yijia Wang (personal communication, BDLilies 2023)
This field verification confirms L. medogense remains extant in its type locality, although likely in very small, isolated populations.
Taxonomy and Relationships
Morphologically, L. medogense belongs to the Himalayan–Southeastern Sinomartagon complex, alongside L. paradoxum and L. lophophorum.
It shares the following traits:
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small bulbs with pigmented scales,
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whorled leaves,
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bell-shaped, unspotted yellow flowers with a dark basal blotch, and
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montane, shaded habitats.
Some authors (Liang 1985; de Wit 1990s notes) suggested affinity with L. paradoxum; the two may represent a geographic cline from Sichuan into southeastern Tibet.
Tentative phylogenetic placement (morphological)
┌── L. paradoxum
┌─────────┤
│ └── L. medogense ← (SE Xizang, 3 000 m; yellow, unspotted)
Section
Sinomartagon ──┤
│
├── L. amoenum
├── L. souliei
└── L. lophophorum
(Molecular confirmation pending; chloroplast genome sequence OR797709 submitted 2024 — Yuan & Gao 2024.)
Cultivation and Conservation
Extremely rare in cultivation; propagation has been attempted through in vitro tissue culture in Chengdu and Yunnan programs.
Prefers cool, well-drained, humus-rich soils, high humidity, and filtered light. Temperatures exceeding 25 °C can cause dormancy failure.
Field conservation is critical due to its tiny range and sensitivity to environmental change.
Evolutionary and Biogeographic Significance
Lilium medogense represents one of the southernmost members of the high-Himalayan Sinomartagon group, surviving in a microclimatic refugium near the Brahmaputra (Yarlung Tsangpo) gorge.
Its morphology indicates adaptation to deep shade and short alpine summers, part of a broader evolutionary radiation that produced L. paradoxum, L. lophophorum, and L. souliei across the eastern plateau.
References
Liang, S. Y. “Lilium medogense, a new species from Xizang.” Acta Phytotaxonomica Sinica 23 (1985): 392.
Flora of China Vol. 24 (2000): 138. Liliaceae: Lilium medogense. Missouri Botanical Garden & Harvard University Herbaria.
Wang, Yijia. “Rediscovery of Lilium medogense.” BDLilies Field Notes (2023).
Yuan, X. & Gao, Y. “Complete chloroplast genome of Lilium medogense (Liliaceae).” GenBank OR797709 (2024).
Duan, Y. et al. “Molecular phylogeny and biogeography of Lilium.” Botanical Journal of the Linnean Society 199 (2022): 323–341.