Meconopsis sect. Impediatae Grey-Wilson, Gen.

Xiao, Wei & Simpson, Beryl B., 2017, A New Infrageneric Classification of Meconopsis (Papaveraceae) Based on a Well-supported Molecular Phylogeny, Systematic Botany (Basel, Switzerland) 42 (2), pp. 226-233 : 231

Meconopsis sect. Impediatae Grey-Wilson, Gen. Meconopsis : 46. 2014.— TYPE: M. impedita Prain.

Monocarpic biennials, or perennials with taproots; up to 1 m tall at anthesis. Stems and leaves aculeate with simple non-barbellate trichomes, or occasionally subglabrous. Leaves senescing and deciduous during the winter. Leaf lamina ovate, oblanceolate to oblong, elliptic to oblong, pinnatifid, or pinnatisect with margins normally entire, lobed or divided, up to 25 cm long. Flowers borne on basal scapes, or in bracteate or ebracteate raceme-like cymes, or both. Petals 4–12, commonly blue or violet, rarely white, yellow, red or dark red. Ovary subspherical, or ellipsoidal to narrowly subcylindric, densely covered by sharp bristles to glabrous; style distinct; stigma capitate or clavate. Capsules oblong, ovoid, obvoid to narrowly subcylindrical. Chromosome number 2 n 5 56, rarely 2 n 5 14.

Included Species — Meconopsis aculeata Royle ; M. bikramii Aswal (a rare species collected from Himalaya Pradesh in India, placed in this section because the original author suggested it is allied to M. aculeate ; no material was available for examination and its palmately lobed lower cauline leaves cast doubt on its affinity); M. concinna Prain ; M. delavayi Franch. Ex Prain ; M. forrestii Prain ; M. georgei G. Taylor ; M. henrici Bureau & Franch. ; M. horridula Hook. f. & Thomson ; M. impedita Prain ; M. lancifolia Franch. ; M. latifolia Prain ; M. muscicola Tosh.Yoshida, H. Sun & Boufford ; M. neglecta G. Taylor ; M. pseudovenusta G. Taylor ; M. pulchela Tosh. Yoshida, H. Sun & Bouford ; M. venusta Prain ; M. yaoshanensis Tosh. Yoshida, H. Sun & Boufford.

As indicated by its name, Meconopsis sect. Aculeatae is characterized by sharp-pointed bristles on leaf and stem surface. Species in this section most commonly bear blue flowers (e.g. Fig. 2D ) or purple-violet flowers (e.g. Fig. 2C ). The flower colors of this section are indicated by branch color in Fig. 3A . The blue-flowered species, form a basal grade to the species with purple-violet flower which suggests that purple-violet is a derived characteristic in this section ( Fig. 3A ). Species with purple-violet flowers tend to be less robust with shorter stature and less dense bristles than the blue-flowered species, and were once believed to resemble the also shortstatured species Meconopsis primulina (the type species of our M. sect. Primulinae). There is overlap at the characters of indumentum, stature, and leaf shape between the species with purple-violet flowers in our M. sect. Aculeatae and those in our M. sect. Primulinae, but the two sections can be easily separated by the petal color ( Fig. 2A, C ). Species in our M. sect. Primulinae do not have the deep purple-violet color of those in M. sect. Aculeatae. Additionally, our M. sect. Primulinae species are distributed mainly in the east Himalaya while the purple-violet flowered species in M. sect. Aculeatae are distributed mainly in the Hengduan Mountains. The phylogenetic evidence also strongly supports the separation of two genetically distant clades of M. sects. Aculeatae and Primulinae.

Figures

FIG. 2. Morphological overview of a species in each of the proposed Meconopsis sections. A. M. bella (in M. sect. Primulinae). B. M. grandis cultivar (in M. sect. Grandes). C. M. sp. (in M. sect. Aculeatae) (possibly a hybrid between named species). D. M. speciosa (in M. sect. Aculeatae). E. M. paniculata (in M. sect. Meconopsis).

FIG. 3. Proposal of new sectional classification of Meconopsis based on cpDNA phylogeny and previous classifications by Fedde (1909), Taylor (1934), and Grey-Wilson (2014).A. Posterior probabilities are labeled above branches. The blue, purple and yellow branches on the phylogeny indicate its terminal taxon’s petal color; and the red branches highlight morphologically distinct species in Meconopsis sect. Meconopsis. Species in the same new section are marked by a color-coded bracket. B–D. The same color codes are used to indicate the placements of taxa we studied under the taxonomic schemes of (B) Fedde (1909), (C) Taylor (1934), and (D) Grey-Wilson (2014).Taxa not tested in our phylogenetic study due to lack of experimental materials are non-shaded in B, C, and D.