Polygonatum luteoverrucosum Floden, 2015

Floden, Aaron J., 2015, Three new Solomon’s Seals (Polygonatum: Asparagaceae) from the Eastern Himalaya, Phytotaxa 236 (3), pp. 273-278 : 276-277

Polygonatum luteoverrucosum Floden , sp. nov. ( Figs. 3–4 )

Similar to Polygonatum oppositifolium (Wall.) Royle and P. angelicum Floden in having opposite evergreen leaves, but it differs in the reddish mature stem coloration, often red leaf midribs, the stem flattened and angled near the leaf petioles, the shorter petioles, and its densely many-flowered (4–14) spherical, umbellate inflorescences. The perigone is yellow, shorter (ca. 1 vs 1.5 cm), and constricted near the middle and verrucose in texture which separates it from P. oppositifolium , but the perigone is yellow in contrast to P. angelicum .

Type:— INDIA. Arunachal Pradesh, East Siang District, above Simong village, ca. 1600 meters, growing epiphytically on various tree species and occasionally on rocks in bryophyte mats, 28.631317, 95.089121, 24 May 2014, A. Floden, Bruggeman, and Prehsler 2764 ( CAL!).

Epiphytic herb. Plant perennial, evergreen. Rhizomes moniliform, torulose, segments oblong to ovoid, ca. 1–2 cm diameter, roots thick and fleshy. Stems terete below the leaves and along the internodes, but flattened near each leaf pair; 30–60 cm long; generally reddish on the lower half of stem, stem arching outward and pendulous; cataphylls very fibrous and persistent. Leaves petiolate, 1–3 mm. Leaves opposite, lanceolate or ovate, 5–12 cm long, distinctly broader in proximal half of leaf, base round to truncate, apex obtuse; coriaceous; dark green adaxially, and lustrous green, rarely glaucous, abaxially; midrib prominent and usually reddish colored, secondary veins equally as prominent as tertiary veins. Inflorescences axillary in most leaf axils; 4–15-flowered; peduncles flattened and deflexed, 0.5–1.5 cm, pedicels 0.3–1 cm, bracteoles minute and subulate or absent. Perigone 8–12 mm, constricted near middle, lobes flared; yellow, surface verrucose. Filaments inserted proximal of the middle (proximal to the constriction of perigone), ca. 1.5–2 mm long; terete, sigmoid and papillose, slightly thicker distally, connivent around stigma; anthers subequal. Ovary green, ovoid, 2–3 mm; style subequal, not surpassing anthers; included in perigone. Fruit spherical, red. Seeds faceted, ca. 1 mm, covered in a distinctive membrane.

Etymology:—Named for the yellow color and the surface texture of the perigone.

Distribution:— CHINA. Tibet, near Medog, 1400–1700 meters. INDIA. Arunachal Pradesh, East Siang District. 1500–1800 meters; this elevation range supports a more subtropical flora than the preceding species.

Phenology:—Flowering May–June, Fruiting October–December (persisting into the next spring).

Other specimens examined (paratypes):— CHINA. Xizang (Tibet Autonomous Region), Medog County, Buqiong , 12 March 1983, 2941 ( PE!) ; ibidem, Beibeng District 1650 m, 12 May 1983, Li Bosheng & Cheng Shuzhi 4856 ( PE!) ; ibidem, 10 March 1983, Li Bosheng & Cheng Shuzhi 2905 ( PE!) ; ibidem, Green Village , 3 August 1980, Plateau Eco Group 11536 ( PE!) ; ibidem, 1750 m, 29 July 1980, Plateau Eco Group 11438 ( PE!) ; ibidem, Jiong Shan 1300 m, 8 September 1974, Qinghai-Tibet Vegetation Team 3128 ( PE!) ; ibidem, Niqiao 1300 m, 30 June 1980, Chenwei Lei 10834 ( PE!) ; ibidem, Beibeng mountain village Medog 1500 m, 4 September 2009, Xiaohua Jin et al SET-ET 1179 ( PE!) ; Hanmi 1800 m, 29 October 1992, H. Sun, Z. K. Zhou, H. Y Zhu 993 ( KUN photo!) ; ibidem 1700 m, 22 October 1992, H. Sun, Z. K. Zhou, H. Y Zhu 2071 ( KUN photo!) ; back hill of Xirab 21000 (sic), 8 December 1992, H. Sun, Z. K. Zhou, H. Y Zhu 2077 ( KUN photo!) ; Buqiong , 1400 m, 18 November 1992, H. Sun, Z. K. Zhou, H. Y Zhu 2164 ( KUN photo!) ; Buqiong , 1400 m, 14 November 1992, H. Sun, Z. K. Zhou, H. Y Zhu 1342 ( KUN photo!) ; Buqiong Lake , 1400 m, 11 November 1992, H. Sun, Z. K. Zhou, H. Y Zhu 1235 ( KUN photo!) ; Nyingchi Prefecture. Motuo Xian, Beibengqu Village, forests, Beibing , 1550 m, 24 June 1983, Li Bosheng & Cheng Shuzhi 5239 ( PE!) .

Taxonomic relationships:—During examination of specimens of Polygonatum luteoverrucosum many collections identified as P. oppositifolium were observed at KUN (digital images) that had been annotated as “ P. medogense H.Li et H.Sun sp. nov.,” an unpublished name. These were later determined as P. oppositifolium (Li Heng, pers. comm.), but are mostly fruiting specimens. Comparisons of P. luteoverrucosum in flower with P. oppositifolium reveal numerous morphological differences in the perigone in addition to molecular differences and confirm their differences. The many-flowered inflorescences borne on short deflexed peduncles and the persistent, fibrous cataphylls are diagnostic and typical of P. luteoverrucosum . Typically the leaves of P. oppositifolium are thinner in texture, and the stem usually green. Moreover the perigone is larger, whitish with red stripes along the center of each tepal, and the surface is smooth. See also under Polygonatum angelicum .

Figures

FIGURE 3. Polygonatum luteoverrucosum photographed in the field by the author at approximately 1600 meters, Arunachal Pradesh, India. Perigone ca. 1 cm long.

FIGURE 4. Polygonatum luteoverrucosum perigone dissected, photographed in the field by the author, showing the insertion point of the filaments and equal ovary and style lengths. Perigone ca. 1 cm long.