This work is licensed under the Creative Commons Attribution 4.0 International License.
Introduction
Trilliaceae, a monocotyledon plant belonging to the family of Liliflorae, is an important officinal group with a medicinal history of over 2,000 years in China. This family includes two genera: Trillium and Paris. The Paris plants have peculiar shape, and their Chinese name (‘Chonglou’) originates from the book South Yunnan Herbals, written by Mao Lan during the reign of the Ming Dynasty. It is so named because a plant from the genera of Paris has only one stem, and one round of leaves grows on this stem; after the plant enters the post-emergence period, a new round of leaf-shaped sepals will emerge from the apex of the leaves; the two rounds of leaves overlapped are similar to the form of a two-floored tower (the meaning of ‘Chonglou’). Around the world, there are 29 Paris species, primarily distributed in the Eurasian tropical and temperate zones. In China, there are about 22 Paris species, most of which grow in the Southwestern provinces, and there are 19 species (including 7 varieties) present in Sichuan Province alone.
Taxonomic treatment
During a survey of plant resources in Dafengding National Natural Reserve in Meigu County, Liangshanzhou, Sichuan Province, the authors gathered a Trilliaceae Paris L. plant from the thick grass present on a hillside. When we observed and recorded its morphological characteristics and ecological environment, we discovered that though these Paris L. plants possessed verticillate leaf blades and flowers, their flowers have only pedicel, calyxes, stamens and pistils, but no petal, which is undoubtedly makes this plant an exceptional species. Based on further observation, studies and consultation of the literature on existing Paris plants [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33], we confirm that this species is a new variety that has not yet been recorded. This new species belongs to the subgenus Daiswa (Raf.) H. Li, Sect. Euthyra Fr. Based on an examination of its morphological characteristics, we have ascertained that it is closely related to the varieties of Paris polyphylla Smith – Paris polyphylla Smith var. panxiensis Liu [5], Paris polyphylla Smith var. stenophylla Franch [1] and Paris polyphylla Smith var. minora Wang [2]. The examination of the morphological characteristics revealed the following unique distinguishing features: blades that are narrowly long, fasciate, and crisped-margined; and having sessile leaves, no petals, tetragonal ovary, and an erect stigma that was never curved during the blooming and fruiting periods; the latter of these collections of features is considered particularly significant owing to the features’ unusual nature. (Table 1 provides greater detail). Therefore, this species is defined as a new variety of Paris polyphylla Smith, and the observation and research results are as reported below.
The main differences in the morphological characteristics between new variety and P. polyphylla Smith var. panxiensis J. L. Liu, P. Polyphylla Smith var. stenophylla Franch and P. Polyphylla Smith var. minora S. F. Wang.
Species
P. polyphylla Smith var. nullopetalina J. L. Liu et Y. Yuan1
Petals compressed-linearis, horizontal and never erect.
Petals compressed-linearis, horizontal and never erect.
Pistil
Ovary tetragonal, stigma 4, erect and never curved.
Ovary globose pentagonal, stigma 5, curved.
Ovary globose pentagonal, stigma 4–5, curved.
Ovary globose pentagonal, stigma 5, curved.
New variety;
Morphology and data of P. polyphylla Smith var. panxiensis Liu are selected from the Acta Botanica Boreali-Occidentalia Sinica [5];
Morphology and data of P. polyphylla Smith var. stenophylla Franch are selected from the Paris L. Plants [1];
Morphology and data of P. polyphylla Smith var. minora S. F. Wang are selected from the Flora of Sichuna [2].
Description
The plant is a perennially erect herb. Its root stock is cylindrical and thick; length is about 3 cm; diameter is about 1.3 cm; and it is fawn-coloured with many dense nodes. The following are the attributes of this newly discovered variety of plant:
Stem: cylindrical, height about 28 cm, diameter about 3–5 mm, glabrous.
Leaf blades: 10, verticillate, chartaceous texture, ribbon-shaped, length 7.6–8.1 cm, width 1.1–1.3 cm; tip and tail acuminate, leaf base broad cuneate or approximately peltate, tip dark green and tail green or sage green, both sides glabrous; triplinerved, midvein sunken at tip and swollen at tail; edge entire, undulate, sessile.
Flower: separate, growing at the apex of stalk, base number 4; pedicel cylindrical, length about 7 cm, glabrous; calyx 4, less and shorter than leaves, verticillate, leaf-shaped, lanceolate, length 4.5–4.7 cm, width 1.1–1.2 cm, tip caudate acuminate to tail, base round, top yellowish-green or green, no stem; no petal; stamen 12, arranged in two rounds, length 1.2–1.5 cm, glabrous; ovary ovoid tetragonal, pale green, height about 5.5 mm, diameter about 4–4.5 mm; style very short or nearly without, style base expanded, four corners discal, humped strongly, thickened, edge dark purple, middle yellowish-green.
Stigma: four, yellowish green, erect in blooming and fruiting periods, never curved, lanceolate, length 8.6–9.5 mm, tip acuminate.
1 Paris polyphylla Smith var. nullopetalina J. L. Liu et Y. Yuan, New Variety, Fig. 1
Subgenus Daiswa (Raf.) H. Li, Sect. Euthyra Fr.
Paris polyphylla Smith var. nullopetalina J. L. Liu et Y. Yuan, var. nov. Fig. 1
A P. polyphylla Smith var. panxiensis J. L. Liu, Paris polyphylla Smith var. stenophylla Franch and Paris polyphylla Smith var. minora S. F. Wang differt foliis sessilibus, petalis absentibus, ovary tetragonal, stigmatibus erectis, non-curvatis.
China. Sichuan, Liangshanzhou, Meiguxian, Dafengding, alt. 3,140 m, in thick growth of grass on mountain slope, 21 July 2006, J. L. Liu 5000 (holotype, deposited into Herbarium of Xichang College, Sichuan).
The new variety is closely related to the other varieties of Paris polyphylla Smith – Paris polyphylla Smith var. panxiensis J. L. Liu, Paris polyphylla Smith var. stenophylla Franch and Paris polyphylla Smith var. minora S. F. Wang, but differs with respect to the following parameters: sessile leaf blade, absence of petal, tetragonal ovary, and stigma erect and never curved.
Identification key for the new variety1and Paris polyphylla Smith var. panxiensis J. L. Liu2, Paris polyphylla Smith var. stenophylla Franch3and Paris polyphylla Smith var. minora S. F. Wang4
1. Flower without petal; tetragonal ovary, stigma erect..............................................................................1. P. polyphylla Smith var. nullopetalina J. L. Liu et Y. Yuan
1. Flower with petal; ovary globose pentagonal, stigma curved.
2. Calyx emerges on petals; petal linear cylindrical, erect, never curved, thickening upward to display rod shape, tip orbicular or blunt; anther connective bulged. ............................................................2. P. polyphylla Smith var. panxiensis J. L. Liu
2. Calyx shorter than or nearly equal to petal; petals compressed-linearis, horizontal and never erect, tapering upward, tip acuminate; anther connective unapparent or obvious linear.
3. Broad leaf blade, length 8–17 cm, width 1.2–3.5 cm, edge straight, short petiolate; anther connective unapparent...........................................3. P. polyphylla Smith var. stenophylla Franch.
3. Narrowly small leaf blade, length about 3 cm, width about 0.7 cm, crisped-margined, sessile; anther connective apparent, linear.......................................................4. P. polyphylla Smith var. minora S. F. Wang
Fig. 1
Paris polyphylla Smith var. nullopetalina flowering plants and habitat.
Fig. 2
Paris polyphylla Smith var. nullopetalina type specimen.
Fig. 3
Paris polyphylla Smith var. nullopetalina flowering plant; J. L. Liu et Y. Yuan 5000 (plant).
