Disporum dorsifixerum Sarapan & Suwanph., 2024
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publication ID |
https://doi.org/10.3767/blumea.2024.69.02.04 |
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persistent identifier |
https://treatment.plazi.org/id/03D31809-FF9C-9C36-3A3F-F955FF3CFCB1 |
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treatment provided by |
Felipe |
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scientific name |
Disporum dorsifixerum Sarapan & Suwanph. |
| status |
sp. nov. |
4. Disporum dorsifixerum Sarapan & Suwanph. , sp. nov. — Fig. 3 View Fig , 4 View Fig , 5 View Fig , 9 View Fig , 10 View Fig ; Map 1
Disporum dorsifixerum has dorsifixed anthers; it differs from D. calcaratum in its flowers which are rotate (vs campanulate in D. calcaratum ); the ridge of the spur that lacks papillae (vs papillose in D. calcaratum ), and the tepals that are apically green (vs pale pink in D. calcaratum ). — Type: A. Sarapan 33 (holo BKF!; iso BK!, BKF!, K!, KKU!,QBG!), Thailand, Lamphun province, Mae Tha district, Doi Khun Tan National Park, 12 June 2021.
Etymology. The specific epithet refers to the dorsifixed anther attachment that is a unique distinguishing character for this species.
Perennial erect herbs. Rhizomes horizontal. Aerial stems 25–160 cm long; the lower part 5–77 cm long, green; the upper part 15– 62 cm long with 2 ridges; distally 2 –6 branched; internodes 1.5–22 cm long. Cataphylls 3–6, 1.5–7.8 by 0.4–2.5 cm, brown or reddish brown. Leaves: lamina narrow-lanceolate to elliptic or ovate, 4.5–14 by 1.8–7 cm, upper surface glabrous, base obtuse, margin dentate, revolute, apex acuminate, veins 3–12; petiole 1–6 mm long, white or green, papillose. Inflorescences umbellate, 2 –10 flowers; peduncle 2 –40 mm long, green. Flowers rotate, 8–20 mm long; pedicel 10–32 mm long, green with purple at proximal and distal ends. Tepals lanceolate to obovate or elliptic to ovate, 1–1.7 by 0.3–0.8 cm, keels 1–3, with papillae, pink or dark purplish red or a dark dull red, base glabrous, margin entire, revolute, apex green. Spurs straight or recurved with a ridge, 5–7 mm long, cylindrical or funnel-shaped, glabrous, pink or light pink or dark purplish red; ridge membranous, glabrous, dark dull red. Stamens 7–14 mm long; filament 4–10 mm long, pink or dark purplish red, smooth; anther dorsifixed, yellow or purplish red. Ovaries globose or obovate, 13–15 by 2 –4 mm, green or pale green to yellow; style 5–10 mm long, dark dull or dark purplish red, papillose. Fruits oblate or globose, 0.4–14 by 0.6–1.4 cm, deep black- ish blue when ripe. Seeds 1–5, subglobose or triangular, light brown to brown, glabrous.
Distribution — Endemic to Thailand (Lamphun: Doi Khun Tan National Park; Tak: Thung Yai Naresuan Wildlife Sanctuary).
Habitat & Ecology — In open areas and along roadsides of mixed deciduous and evergreen forests at 1300–1800 m elevation. Flowering: July to August; fruiting: July to December.
Preliminary IUCN conservation status — A conservation status of Vulnerable (VUD2) is proposed. Disporum dorsifixerum is endemic to Thailand and is known from two localities, each with a small population where a few individuals were observed. The species might occur in other areas in the Northern region of Thailand. A further survey is needed to reassess the conservation status.
Anatomical characters — Upper stem: two ridges. Petiole V-shaped with ridges. Leaves: upper epidermal cells above costal zone with echinate cuticles and intercostal zone with smooth cuticles ( Fig. 3l View Fig ); lower epidermal cells of costal zone with echinate cuticles ( Fig. 4e View Fig ) and intercostal zone with smooth cuticles; margin slightly revolute; anticlinal walls of adaxial epidermis sinuate ( Fig. 4j View Fig ).
Pollen morphological characters — For polar and equatorial views see Fig. 5m, n View Fig .
Pollen in equatorial view asymmetrical, spheroidal (P/E = 1.03–1.12 µm), medium-sized (27–29 by 25–27 µm). Aperture triporate ( Fig. 5o View Fig ). Exine 1–3 ± 0.52 µm thick; ornamentation rugulate with granulate surface ( Fig. 5p View Fig ).
Note — Disporum dorsifixerum is similar to D. calcaratum in its pink to purple perianth. The differences are provided in Table 3.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.