Iris dabashanensis C.A.Wilson, 2020

Wilson, Carol A., 2020, Two new species in Iris series Chinenses (Iridaceae) from south-central China, PhytoKeys 161, pp. 41-60 : 41

Iris dabashanensis C.A.Wilson sp. nov. Figures 2A-C , 3

Diagnosis.

Morphologically similar to I. henryi the new species differs in having narrower leaves (0.9-2 mm versus 4-4.5 mm), shorter bracts (2-4 cm versus 4-7 cm), and shorter style branches (1 cm versus 1.8 cm).

Type.

China. Sichuan Province: About 5 km N of Wanyuan, Wanyuan County, 1,140 m, 32°11.720'N, 108°05.310'E, 3, May 2001 (fl), voucher from cultivated material, D. Probst CPC3.5.01.3 (holotype: UC!; isotypes: PE!, E!).

Description.

Small evergreen herbaceous plant with aerial flowering stems less than basal leaves. Bracts, cauline leaves, base of basal leaves ± tinged with red. Rhizomes short and branched with fibrous leaf remains. Stolons present. Roots slender, branched, with tubers to 6 mm. Basal leaves distichous, linear with acute apex, bright green, slightly glossy, 28-44 cm long, 0.9-2 (3) mm wide, 1-2 veins; crowded in clumps. Flowering stem ca. 8-18 cm with 1 or 2 cauline leaves, with upper cauline leaf extending well above mid stem. Inflorescence with two opposite bracts (spathes) subtending 2 (3) flowers, terminal flower opening first with a single bract subtending each subsequent flower; lower bracts ± equal, 2.0-4 cm long, 0.4-0.5 cm wide; pedicels long (2.5-5 cm) and slender. Flowers light violet, open, ca. 3 cm diameter, radial with petals slightly angled upward, sepals light violet, horizontal and recurved distally; floral tube 0.2-0.5 cm; sepals ovate, shallow apical notch, narrowed at base, 2-3 cm long, 0.6-1.1 cm wide, obvious median ridge cream-colored with violet spots, a lateral ridge on either side of the median, yellow patch between lateral ridges and extending beyond ridges; petals light violet, rotund, apical notch, 1.6-2.1 cm long, ca. 1.0 cm wide, clawed in lower 1/4; stamens cream, ca. 0.8 cm long, anthers = filaments; style branches petaloid, light violet, ca. 1 cm long, 0.3 cm wide, bi-lobed distally, lobes ca. 0.4 cm long, stigma broad, slightly rounded. Capsule rounded, ca. 1 cm long. Seed light to medium brown, ca. 0.4 cm, with conspicuous white appendage. Flowering: April to May.

Distribution and ecology.

Iris dabashanensis is known from the Daba Mountains in Sichuan and Hubei Provinces and Chongqing Municipality (Fig. 4 ) on open rocky slopes with calcareous soils associated with shrubs or mixed conifer and hardwood forests.

Etymology.

The new species is named for the Daba Mountains in China where it occurs.

Preliminary conservation status.

Following the criteria and categories of IUCN (2012), Iris dabashanensis is given a preliminary status of Least Concern (LC). One of the known populations is in the Shennongjia Forest Region of Hubei Province. Although the precise location of the I. dabashanensis population is unknown, the Shennongjia National Nature Reserve occurs within the region and has protected status.

Other specimens examined.

China. 4 ⚥ Chongqing Municipality, Chengkou County; 29 April 1958; T.L. Dai leg.; 100265; HNWP 34156, PE 01012365, SZ 00043052, SZ 00043057; · 5 ⚥ Chongqing Municipality: Chengkou County; 1 May 1958; T.L. Dai leg.; 100335; CDBI 0169543, IBK 00251078, SZ 00043056, PE 00034001, PE 01012364; · 4 ⚥ Chongqing Municipality: Liangzhong Hewu ji, Chengkou County; 20 April 1958; T.L. Dai leg.; 100150; PE 00034002, SZ 00043055, HNWP 34209, IBK 00251010; · 1 ⚥ Chongqing Municipality: Liang Yizh, Chengkou County; 2 April 1958; T.L. Dai leg.; 100154; CDBI 0169546; · 6 ⚥ Chongqing Municipality: Yizi Liang Hengyan pengwuji, Chengkou County; 24 May 1958; T.L. Dai leg.; 100583; IBK 00081641, CDBI 0169544, CDBI 0169545, HNWP 34583, SZ 00043061, PE 01012366; · 1 ⚥ Chongqing Municipality: Chengkou County; sin. date; Farges leg.; 101; P 02163317; · 4 ⚥ Chongqing Municipality: Chengkou County; 1892; Farges leg.; 1024; P 02163312, P 02163313, P 02163314, P 02163316; · 11 ⚥; Hubei Province: Shennongjia Forest Region; 27 April 2014; Du Wei leg.; 1407; WH 1933.

Notes.

The date on the specimen T.L. Dai 100154 was 1918 but the collections made at the same time and place had a date of 1958 which is consistent with Dai’s numbering of specimens and other collections.

Figures

Figure 2. Images A-C I. dabashanensis D-F I probstii. A Habit B inflorescence C flower D habit E inflorescence F flower (Photos B-F C. author; A Mark McDonough).

Figure 3. Illustration of I. dabashanensis. A Habit B inflorescence C sepal D petal E style branch, anther F fruit G stolon, roots, tubers H root tuber (Source: A-E D. Probst CPC 3.5.01.3 (UC); F photograph by Marty Schafer and Jan Sacks; G, H photograph by D. Probst, photographs available from author).

Figure 4. Map of known distribution for I. dabashanensis in gray outlined in black.