Tuesday, February 13, 2024

[Botany • 2024] Piper motuoense (Piperaceae) • A New Species from Xizang, China

 

Piper motuoense X.W.Qin, F.Su & C.Y.Hao,

in Su, Qin, Fan, Yan, Ji et Hao. 2024. 
墨脱胡椒  ||  DOI: 10.3897/phytokeys.238.115494

Abstract
Piper motuoense X.W.Qin, F.Su & C.Y.Hao, a new species of Piperaceae from Xizang, China, is described and illustrated in this paper. The new species resembles P. yinkiangense and P. anisotis, but it can be readily distinguished from the compared species by several characteristics. Gonophyll leaves are chartaceous and the leaf secondary vein count is 7–9, with the outermost pair being very weak when there are nine veins. Additionally, the apical pair arises 2–4 cm above the base and the leaf base is asymmetrical, with bilateral petioles that cling and heal together. Pistillate floral bracts are sessile, with 3, 4 or 5 stigmas. The description of the new species includes photographs, detailed descriptions, notes on etymology, distribution and habitat, as well as comparisons with morphologically similar species.

Key words: Asia, Paleotropical flora, Piperales, Sino-Himalaya, taxonomy

Line drawing of Piper motuoense X.W.Qin, F.Su & C.Y.Hao, sp. nov.
A branch with infructescence B branch with staminate spike C magnified view of pistillate spike D magnified view of staminate spike E magnified view of infructescence F detail of the indument along the secondary nerves of the abaxial leaf surface G adaxial surface of gonophyll leaf H adaxial surface of gonophyll leaf base I abaxial surface of gonophyll leaf J abaxial surface of gonophyll leaf base K cross-section of infructescence L stamen M carpel N seed.
Illustration by Fan Su, based on the holotype.


Piper motuoense X.W.Qin, F.Su & C.Y.Hao, sp. nov.
A habit B branch with infructescence C branch with staminate spike D branch with trophophyll leaf E adaxial and abaxial surface of gonophyll leaf F adaxial and abaxial surface of gonophyll leaf base G detail of the indument along the mid-vein of the gonophyll leaf adaxial and abaxial surface H pistillate spike I staminate spike J infructescence K close-up of portion of the staminate spike L close-up of portion of the infructescence M cross-section of infructescence N seed (side view).
Photographs by Fan Su.

 Piper motuoense X.W.Qin, F.Su & C.Y.Hao, sp. nov.
 
Diagnosis: The new species is morphologically similar to P. yinkiangense, but can be easily distinguished from the latter in several aspects. The leaf-blades 12.5–18 × 3.5–6.5 cm, elliptic or ovate to lanceolate (vs. 11–14 × 6.5–8.5 cm, oblique-ovate), chartaceous (vs. membranous), abaxially sparsely villous along the mid-vein (vs. abaxially sparsely hispidulous), gonophyll leaves 7–9 secondary vein pairs, the outer pair arising 2–4 cm above base (vs. 8–9, outer pair arising 1–2 cm above base), base bilaterally clinging to the petiole and overlap together (vs. basal sinus 1–2 mm wide on side of longer and wider lobe, 4–5 mm wide on other side, bilaterally free for 2–3 mm), floral bracts sessile (vs. petiolate) and stigmas 3, 4 or 5 (vs. 4). P. motuoense also resembles P. anisotis in the shape of leaves and fruit, but differs from the latter in the leaves vein 7–9 (vs. 5–7), leave base bilateral clinging to petiole and overlap together (vs. bilateral free for 1–2 mm) (Table 1).

Etymology: The specific epithet refers to its distribution, Motuo County, Xizang, in China.

Vernacular name: Chinese: 墨脱胡椒 (mò tuō hú jiāo). ‘Mò Tuō’ is a place name, which is the literal translation of the specific epithet motuoense and ‘hú jiāo’ is the Chinese name of Piper.


 Fan Su, Xiao-Wei Qin, Rui Fan, Lin Yan, Xun-Zhi Ji and Chao-Yun Hao. 2024. Piper motuoense, A New Species of Piperaceae from Xizang, China. PhytoKeys. 238: 85-94. DOI: 10.3897/phytokeys.238.115494