The Confusing Identity of Pternopetalum Molle (Apiaceae)
Total Page:16
File Type:pdf, Size:1020Kb
Botanical Journal of the Linnean Society, 2008, 158, 274–295. With 15 figures The confusing identity of Pternopetalum molle (Apiaceae) LI-SONG WANG1,2* 1State Key Laboratory of Systematics and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Xiangshan, Beijing 100093, China 2Graduate School of Chinese Academy of Sciences, Beijing 100039, China Received 25 April 2006; accepted for publication 24 June 2008 The misapplication of the name Pternopetalum molle (Franch.) Hand.-Mazz. has resulted in considerable taxonomic confusion in the genus, involving 11 names belonging to seven taxa (according to a recent treatment). A supplementary taxonomic revision of P. botrychioides (Dunn) Hand.-Mazz., P. molle and P. vulgare (Dunn) Hand.-Mazz. is presented, after a detailed examination of the morphological variation. Four new synonyms, P. longicaule var. humile R.H.Shan & F.T.Pu, P. molle var. dissectum R.H.Shan & F.T.Pu, P. radiatum (W.W.Smith) P.K.Mukherjee and P. trifoliatum R.H.Shan & F.T.Pu, are proposed. Pternopetalum delicatulum (H.Wolff) Hand.- Mazz. should be reduced to P. botrychioides rather than P. radiatum. The previous taxonomic treatments of P. cuneifolium (H. Wolff) Hand.-Mazz., P. cartilagineum C.Y.Wu ex R.H.Shan & F.T.Pu and P. molle var. crenulatum R.H.Shan & F.T.Pu are reinstated. A key and distribution maps are provided for the accepted species. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295. ADDITIONAL KEYWORDS: East Asia – morphology – taxonomic revision – Umbelliferae. INTRODUCTION subfamily Apioideae (Pu, 1985; Pimenov & Leonov, 1993), two morphological characters, petals saccate at Pternopetalum Franch., one of the largest genera of the base and umbellules usually with only 2–3(–4) Apiaceae in Asia (Pimenov & Leonov, 2004), includes flowers (Shen et al., 1985; Pu, 2001; Pu & Phillippe, about 20–32 taxa which occur in South Korea, Japan, 2005), make it relatively easy to identify. It seems to China and the adjacent eastern Himalayan regions be a natural genus in Apiaceae (Valiejo-Roman et al., (Pu, 1985; Mukherjee & Constance, 1993; Pimenov 2002). & Leonov, 1993; Ohba, 1999; Watson, 1999; Pu & Detailed taxonomic scrutiny is hindered by inad- Phillippe, 2005), with a centre of diversity in west equate herbarium specimens and a lack of adequate Sichuan, north-west Yunnan and south-eastern Tibet field surveys, making it one of the more difficult (Shu & Sheh, 2001). As a genus endemic to the East groups in Apiaceae (M. F. Watson, Royal Botanic Asian flora (Wu, 1991; Wu et al., 2006), its phytogeog- Garden, Edinburgh, pers. comm.). Some taxa still raphy has been documented by many authors remain uncertain in the recently published Flora of (Constance, 1972; Takhtajan, 1986; Sheh & Su, 1987; China (Pu & Phillippe, 2005). The generic review Pu, 1996; Sun, 2002; Wu et al., 2003). Pternopetalum revealed that the misapplication of the name Pterno- species are mainly erect perennials with a distinct petalum molle (Franch.) Hand.-Mazz. was the great- rootstock on which the radical leaves are produced est source of confusion in this genus. each year. These plants usually grow in shady and Pternopetalum molle was first recognized by moist evergreen forest, especially in mountain areas Franchet (1894) based on Delavay, J. M. 4095 with rich streams. As part of the tribe Apieae of the (Figs 1A, 2A, B). This species is characterized by an annual habit, delicate appearance, single and fusi- *E-mail: [email protected] form root, and terminal and lateral umbels, that 274 © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295 IDENTITY OF PTERNOPETALUM MOLLE 275 Figure 1. A, Holotype of Pternopetalum molle, Delavay J. M. 4095 conserved at P. B, Pternopetalum cuneifolium, specimen referred to as P. molle in previous flora treatments, Ching, R. C. 22416 conserved at PE. Figure 2. Illustration of Pternopetalum molle: A, plant; B, fruits, illustrated from Delavay 4095 conserved at P; C, illustration of P. molle, photocopied from Shan, R. H. & Pu, F. T. 1978 with modification; this illustration was also used in Flora Reipublicae Popularis Sinicae (1985). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295 276 L.-S. WANG Figure 3. Underground part of perennial and annual species of Pternopetalum:A,P. cuneifolium (Wang, Lisong 0039, PE); B, P. vulgare (Wang, Lisong 0037, PE); C, P. radiatum (Grierson A. J. C. & Long D. G. 1855, E). cannot be confused with other species of Pternopeta- consulted. The software packages BRAHMS 5.58 lum. However, in a later generic review (Shan & Pu, (http://herbaria.plants.ox.ac.uk/bol/home/) and DIVA- 1978), a perennial collected by R. C. Ching 22416 GIS 5.2 (http://www.diva-gis.org/) were used to (Fig. 1B) was illustrated and referred to Franchet’s P. manage specimen datasets and to produce distribu- molle (Fig. 2B). At the same time, four new taxa (P. tion maps. The characters associated with fruits and molle var. crenulatum R.H.Shan & F.T.Pu, P. molle the blade indumentum were examined, and photo- var. dissectum R.H.Shan & F.T.Pu, P. cartilagineum graphs were taken with an NDigital Camera C.Y.Wu ex R.H.Shan & F.T.Pu and P. longicaule var. DXM1200F and scanning electron microscope. humile R.H.Shan & F.T.Pu) were described in this work. The concept of P. molle in Shan & Pu (1978) was to remain in later national Chinese and local DIAGNOSTIC CHARACTERS EXAMINED flora treatments (Pu, 1985, 1993; Pan, 1997). As a HABIT AND UNDERGROUND PARTS result, controversial treatments involving P. cuneifo- Plants of Pternopetalum are mainly perennial having a lium (H. Wolff) Hand.-Mazz., P. cartilagineum and P. visible short caudex on which the leaf-sheath remains molle var. crenulatum appeared. In Flora Yunnanica are preserved (for example, P. botrychioides, P. cunei- (Pan, 1997), P. cuneifolium was accepted as a distinct folium and P. vulgare) (Figs 1B, 3A, B, 4–7). Pterno- species with P. cartilagineum and P. molle var. crenu- petalum longicaule var. humile, P. radiatum, P. latum as synonyms, whereas, in the recently pub- trifoliatum and P. molle (sensu Franchet) are annuals. lished Flora of China (Pu & Phillippe, 2005), P. These plants bear a single fusiform and somewhat cartilagineum was reinstated as a distinct species, herbaceous root, usually no more than 3 cm in length and P. cuneifolium and P. molle var. crenulatum were (Fig. 3C). The root is easily broken from the stem reduced to P. molle. and is often not visible on herbarium specimens The aim of this study is to clarify the taxonomic (Figs 1A, 8B, 9). Annuals have an almost uniform identity of P. molle, and re-examine its morphological appearance to their underground parts, whereas those delimitation with P. longicaule var. humile, P. radia- of perennials vary from well branched to single and tum and P. trifoliatum. A supplementary revision is thickened rootlets (Fig. 3A, B) in response to different also provided for the other taxa confused with P. molle. habitat water availability. Pternopetalum caespitosum R.H.Shan has been recorded as an annual (Pu, 1985), MATERIAL AND METHODS but field investigations and examination of morpho- logical characters show that it is a typical perennial. Morphological variation was evaluated on herbarium material preserved at the following herbaria: BM, CDBI, E, GH, HGAS, IBSC, K, KUN, NAS, P, PE, STEMS AND LEAVES SM, SZ and SWFC (herbarium abbreviations follow In earlier descriptions of species (Shan & Pu, 1978; Holmgren, Holmgren & Barnett, 1990). Field investi- Pu, 1985, 2001; Pu & Phillippe, 2005), variations in gations were carried out by the author in Guizhou, the main stem were reported as ‘stem branched/ Sichuan and Yunnan Provinces, China, during several unbranched’, or ‘stems one to several’. However, as visits in the period 2003–2005. Type specimens and observed in most Apiaceae by Kljuykov (Kljuykov original descriptions were carefully examined to et al., 2004), the stems of Pternopetalum can be well assess critical diagnostic characters. Photographs of developed or not. Not all perennial species have a types from GH, L, MO, NY, UC and WU were also well-developed main stem. They usually have a © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295 IDENTITY OF PTERNOPETALUM MOLLE 277 Figure 4. A, Holotype of Pternopetalum cuneifolium, Maire, E. E. 620 conserved at E. B, Holotype of P. cartilagineum, Wang, Q. W. 72593 conserved at KUN. Figure 5. A, Lectotype of Pternopetalum molle var. crenulatum, Tsai, H. T. 55935A conserved at IBSC. B, Isolectotype of P. molle var. crenulatum, Tsai, H. T. 55935 conserved at GH. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295 278 L.-S. WANG Figure 6. A, Lectotype of Pternopetalum vulgare, Henry, A. 10675 conserved at K. B, Holotype of P. molle var. dissectum, Feng, K. M. 4800 conserved at KUN. Figure 7. A, Lectotype of Pternopetalum botrychioides, Pratt, A. E. 839 conserved at K. B, Isotype of P. delicatulum, Limpricht 1498 conserved at WU. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295 IDENTITY OF PTERNOPETALUM MOLLE 279 Figure 8. A, Isolectotype of Pternopetalum radiatum, Gammie, G. A. 992 conserved at K. B, Pternopetalum radiatum, Wood, J.R.I. 6450 conserved at E. Figure 9. A, Holotype of Pternopetalum longicaule var. humile, Liu, T. N. et al. 1310 conserved at PE. B, Holotype of P. trifoliatum, Zhou, B. K. et Pu, F. T. 211 conserved at CDBI. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 274–295 280 L.-S. WANG Figure 10.