Corresponding author: Yanqin Xu (yqxu1980@163.com)
Academic editor: P. Stoev
Due to some common or similar features (e.g., small leaf, spurless, yellow flower), three Chinese species of the genus
Liu S, Liu L, Huang X, Zhu Y, Xu Y (2017) A taxonomic revision of three Chinese spurless speciesof genus
As a traditional Chinese herbal medicine,
However,
On the other hand, numerous
Based on extensive studies of the three spurless
Field investigations on the germplasm resource and morphological observations have been conducted from 2012 to 2016. Field work was done in Hubei, Shanxi, Chongqing and Sichuan Province, China. A total of 120 individuals (30 individuals per population) from four populations of three spurless species,
Location and habitat characters of populations of
Species | Population code | Location (China) | Elevation (m) | Latitude (N) | Longitude (E) | Collect date |
---|---|---|---|---|---|---|
|
SCLD | Longdong, Baoxing, Sichuan | 1641 | 102°44' | 30°26' | 2015.4.12 |
SCBX | Muping, Baoxing, Sichuan | 1426 | 102°50' | 30°22' | 2015.4.14 | |
|
SXLP | Yuanba, Nanzhen, Shanxi | 1263 | 106°36' | 32°51' | 2016.4.26 |
|
SCLC | Longchi, Dujiangyan, Sichuan | 1937 | 103°35' | 31°09' | 2016.5.6 |
All 120 individuals of the three species were transplanted at the
Based on field investigations and herbarium specimens,
Geographic distribution (black symbols) and sampling populations (white symbols) of
Quantitative morphological data from
Quantitative traits (mean ± SD) comparative analysis of populations of
Species |
|
|
|
|
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Population code | SCLD | SCBX | SXLP | SCLC |
Height of flowering stem (cm) | 25.17±5.43 | 34.53±6.83 | 29.73±5.84 | 42.30±7.70 |
Length of inflorescence (cm) | 12.93±3.40 | 12.40±2.74 | 9.46±2.51 | 17.12±5.84 |
Number of flowers | 9±3 | 10±2 | 4±1 | 25±11 |
The length of middle leaflet (cm) | 3.01±0.58 | 3.32±0.54 | 4.35±0.48 | 5.26±0.71 |
The width of middle leaflet (cm) | 2.30±0.37 | 2.48±0.44 | 4.02±0.49 | 3.37±0.83 |
The length/ width of middle leaflet | 1.31±0.15 | 1.35±0.12 | 1.08±0.07 | 1.62±0.28 |
Rhizome diameter (mm) | 1.71±0.73 | 1.69±0.33 | 1.97±0.56 | 5.12±1.28 |
The main discrete morphological characters of
The main discrete morphological characters comparative analysis of populations of
Species |
|
|
|
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Shape of petals | Obviate, apex subacute | Oblong, apex rounded | Obviate, apex rounded |
Shape of inner sepals | Elliptic | Ovate | Ovate |
Colour of inner sepals | Purple-red | Purple-red | Red-tinged |
Pedicel indumentum | Glandular hairs | Glandular hairs | Glandular hairs |
Inflorescence | Raceme | Raceme | Panicle |
Inflorescence indumentum | Glandular hairs | Almost glabrous | Almost glabrous |
Shape of leaves | Ovate | Subrounded | Ovate |
Blade back indumentum | Pilose | Sparingly pilose | Pilose, vein evident |
Petiolule indumentum | Pilose | Glabrous | Almost glabrous |
Stem-leaves | Two alternate or opposite trifoliolate leaves | One trifoliolate leaves, sometimes two opposite trifoliolate leaves | Two alternate or opposite trifoliolate/5-foliolate leaves, sometimes three alternate trifoliolate leaves |
Rhizome | Long creeping | Thin, short or long-creeping | Compact |
Flowering stem 20–40 cm long. Rhizome long creeping, 1–3 mm in diameter. Leaves basal and cauline, trifoliolate, 5-foliolate, sometimes 7-foliolate; leaflets ovate, 2.5–4 × 2–3 cm, apex acuminate, base deeply cordate with regularly rounded lobes, terminal leaflet with equal rounded lobes, lateral leaflets oblique with outer lobe large and rounded, inner lobe smaller and rounded, margin spinose-serrate, abaxially long-pilose. Flowering stem usually with two alternate or opposite trifoliolate leaves, or sometimes three alternate trifoliolate leaves, occasionally two opposite 5-foliolate leaves, rarely three or four whorled leaves with unifoliolate, trifoliolate and/or 5-foliolate. Inflorescence raceme, 7–14-flowered, 10–16 cm long, glandular hairs. Flowers ca. 10 mm in diam., yellow, pedicels 1–2 cm long, glandular hairy. Outer sepals 4, pale purple, broadly ovate, ca. 4 × 1.5 mm. Inner sepals 4, purple-red, elliptic, ca. 5 × 1.5 mm. Petals 4, yellow, or sometimes purple-red spotted at base, spurless, ca. 6–8 × 4–5 mm, obovate, apex subacute. Stamens ca. 4.5 mm; anthers yellow, ca. 1.5 mm.
Photos of
Flowering stem 25–35 cm long. Rhizome thin, short or long-creeping, 1–3 mm in diameter. Leaves basal and cauline, trifoliolate; leaflets subrounded, ca. 4.5 × 4 cm, apex rounded, base deeply cordate with regularly rounded lobes, terminal leaflet with equal rounded lobes, lateral leaflets oblique with outer lobe large and rounded, inner lobe smaller and rounded, margin spinose-serrate, abaxially pilose. Flowering stem with 1 trifoliolate (rarely 5-foliolate) leaves, sometimes 2 opposite trifoliolate leaves, occasionally 2 opposite unifoliolate leaves. Inflorescence raceme, 2–6-flowered, 7–12 cm long, almost glabrous. Flowers ca. 10 mm in diameter, yellow, pedicels 0.5–1 cm long, glandular hairs. Outer sepals 4, green, triangular-lanceolate, ca. 2 ×1 mm. Inner sepals 4, purple-red, ovate, ca. 4 × 1.5 mm. Petals 4, yellow, spurless, ca. 6–8 × 4–5 mm, oblong, apex rounded. Stamens ca. 3 mm; anthers yellow, ca. 2 mm.
Population variation of leaves morphology in
Flowering stem 35–50 cm long. Rhizome compact, 4–6 mm in diameter. Leaves basal and cauline, trifoliolate; leaflets ovate, 4.5–6 × 2.5–4 cm, vein evident, apex rounded, base deeply cordate with regularly rounded lobes, terminal leaflet with equal rounded lobes, lateral leaflets oblique with outer lobe large and rounded, inner lobe smaller and rounded, margin spinose-serrate, abaxially pilose. Flowering stem usually with 2 alternate (mostly 2 trifoliolate and occasional 1 trifoliolate and 1 unifoliolate) or opposite leaves, sometimes 3 alternate leaves, and 1 trifoliolate leaves also occasionally observed. Inflorescence panicle, 15–43-flowered, 11–23 cm long, almost glabrous. Flowers ca. 10 mm in diam., yellow, pedicels 1.2–1.8 cm long, glandular hairs. Outer sepals 4, green, broadly ovate, ca. 2 ×2.5 mm. Inner sepals 4, red-tinged, ovate, ca. 2.5–3 × 1–1.5 mm. Petals 4, yellow, spurless, ca. 6–8 × 5–7 mm, obovate, apex rounded. Stamens ca. 2.5 mm; anthers yellow, ca. 1 mm.
Only known from Dujiangyan, Sichuan,
1 | Flower ca. 7 mm; petals are flat with slightly cucullate base; leaflets are thickly leathery |
|
– | Flower ca. 10 mm; petals are flat; leaflets are membranaceous. | |
2 | Rhizome compact, diameter 4–6 mm; inflorescence panicle |
|
– | Rhizome long creeping, diameter 1–3 mm; inflorescence raceme. | |
3 | Inflorescence usually 7–14-Flowered, two alternate or opposite trifoliolate leaves |
|
– | Inflorescence usually 2–6-Flowered, one trifoliolate leaf, sometimes two opposite trifoliolate leaves |
|
The protologue (
Due to the slender elongated rhizome and small broadly ovate or almost orbicular leaflets, Guo et al. (1993) described a variety,
The number of stem-leaves was believed to be stable within a species and important for taxonomy, and three informal groups have been divided by the normal number of stem-leaves (
It is significant that the comparatively unstable species occur in western China, where the genus is best represented and where its evolution may still be proceeding (
The protologue for
Although having much in common with
Despite similarity in leaf size and flat, suprless, yellow flowers,
Comparison of key characteristics of
Species |
|
|
|
---|---|---|---|
Shape of petals | Obovate, apex subacute | Oblong, apex rounded | Obovate, apex rounded |
Inner sepals | Purple-red, elliptic | Purple-red, ovate | Red-tinged, ovate |
Number of flowers | 7–14 | 2–6 | 15–43 |
Inflorescence | Raceme, 10–16 cm | Raceme, 7–12 cm | Panicle, 11–23 cm |
Leaves | Ovate, 2.5–4 × 2–3 cm | Subrounded, ca. 4.5 × 4 cm | Ovate, 4.5–6 × 2.5–4 cm |
Stem-leaves | Two alternate or opposite trifoliolate leaves | One trifoliolate leaves, sometimes two opposite trifoliolate leaves | Two alternate or opposite trifoliolate/5-foliolate leaves, sometimes three alternate trifoliolate leaves |
Rhizome | Long creeping, 1–3 mm | Thin, short or long-creeping, 1–3 mm | Compact, 4–6 mm |
This research was supported by the National Science Foundation of China (31360036; 31100146), and Young Scientists Fellowship of Jiangxi Province (20133BCB23024).