THAI JOURNAL OF BOTANY 1(1): 43–48. 2009. FQBIQB=C HGQI4Ba6A 1(1): 43–48. 2552. Taxonomic notes on Thai Parnassia L. (Parnassiaceae) and threats to them PIYAKASET S UKSATHAN * Herbarium, Queen Sirikit Botanic Garden, The Botanical Garden Organization, Mae Rim, Chiang Mai, 50180, Thailand. ABSTRACT . Previous herbaria and literature studies have led to the recognition of three species of Parnassia L. in Thailand, P. mysorensis Heyne ex Wight & Arn., P. siamensis Shimizu and P. wightiana Wall. ex Wight & Arn. Recent fieldwork in northern Thailand has revealed large variation in characters traditionally ascribed diagnostic value, which suggests that P. siamensis is probably conspecific with P. mysorensis . The consequence of these findings may well be that the size of the genus worldwide is overestimated. Parnassia is endangered in Thailand by various threats, the most imminent ones are being forest fire, cattle grazing and invasive weeds. Excessive collection for herbarium specimens imposes an increasing threat. KEYWORDS : Taxonomy, Parnassiaceae, Parnassia , Thailand. INTRODUCTION The genus is fairly homogeneous with many unique morphological characters, Parnassia is a genus of small perennial i.e ., solitary, terminal, bisexual and mountain herbs in various open-moist pentamerous flowers with antipetalous habitats, including rock outcrops, bogs, wet staminodes (Simmons, 2004). Its systematic meadows and grasslands. The genus consists position has, however, long been in dispute. of ca. 70 species distributed from arctic- Hooker & Thomson (1858), Engler (1930) alpine regions of the northern hemisphere to and Cronquist (1981) treated Parnassia as N Mexico, Morocco and N Sumatra with a a member of Saxifragaceae. It has also center of diversity in Himalayan-China ( ca. 59 been suggested by several works to be closely species, 46 endemic). (Ku, 1987, 1995; Wu et al ., related to Droseraceae, Hypericaceae, or even 2003; Simmons, 2004). Nymphaeaceae (Hallier, 1901; Arber, 1913), while some botanists have agreed to place * Corresponding author: [email protected] it in its own family, Parnassiaceae (Gray, Received: 7 June 2009 1821). Recent molecular systematic studies Accepted: 23 June 2009 44 Suksathan have confirmed that Parnassiaceae, including ing that size of the genus worldwide, espe- Parnassia and Lepuropetalon Elliott should cially in China, could be overestimated. be retained separately as a sister to Celastraceae (APGII, 2003; Chase et al. , Staminode shape 1993; Soltis et al. , 2000). In Thai material of P. mysorensis the staminode shape varies from simple MORPHOLOGICAL V ARIATION cylindrical, dilate to discoid, or sometimes dilate with 2-3 regular to irregular lobes, the Recent fieldwork in N Thailand has lobes with or without a knoblike apex revealed large variation in characters (Table 1 & Fig. 1A). Similarly in P. siamensis , traditionally ascribed diagnostic value, i.e., the staminode shape varies from simple staminode shape, petal punctation, petal undulated-discoid to apex dilate with 2-3 margin, and cauline leaf position. These irregular lobes, or to candelabriform, the characters are frequently used for classifi- lobes with or without a knoblike apex cation of sections and species in several (Table 1 & Fig. 1B). Using these variable treatments (Clarke, 1879; Engler, 1930; Ku, characters with keys and descriptions 1987, 1995; Gu & Hultgård, 2001). In provided in the Flora of China (Gu & Hultgård, China many closely related species are rec- 2001), three to six species would possibly ognised by a combination of these variable occur in one place. characters (Gu & Hultgård, 2001), suggest- Table 1 . Variation of staminode shape in two species of Thai Parnassia from four localities in N Thailand. Species names Altitudes (m) Staminode shapes Voucher & Localities specimens P. mysorensis 1,700 - discoid with 0-4 shallow lobe(s) Suksathan 2809 (QBG) Doi Pui, - dilate with 2-3 regular-irregular lobes Mae Hong Son - lobe-apex simple or +- knob-like P. mysorensis 1,500-1,800 - simple, dilate Suksathan 3057 (QBG), Doi Phe Pan Nam, - dilate with 2-3 irregular lobes 2873 (QBG) Chiang Rai - lobe-apex simple or +- knob-like P. mysorensis 1,650 - simple, cylindrical Suksathan 3592 (QBG) Doi Hua Suea, - 3 irregular lobes Chiang Mai P. siamensis 2,200 - discoid with 4-7 shallow lobes Suksathan s.n. (QBG) Doi Chiang Dao, - candelabriform Chiang Mai - dilate 2-3 irregular lobes - lobe-apex simple or +- knob-like Thai Parnassia and threats to them. 45 Petal punctation Thai species ( P. mysorensis and P. siamensis ), This character seems to vary in dry petal margins vary from subentire, erose, specimens. The punctate petals are clearly shortly fimbriate proximally or throughout visible in old specimens ( P. mysorensis: (Table 1. & Fig. 1A–B). Garrett 702 , BKF), while it is rarely present in newly collected specimens of the same Cauline leaf position species from a locality nearby ( Watthana et Different positions of cauline leaf on al. 584 , QBG). the scape, i.e., near the middle, near the base, or near the apex are also used in the Petal margin Chinese keys (Gu & Hultgård, 2001). In Petal margin is also one of main Thai plants this character seems, however, characters used in several keys. For two to vary within the same population. Figure 1. Petals and staminodes A. Parnassia mysorensis Heyne ex Wight & Arn.; B. P. siamensis Shimizu; C. P. wightiana Wall. ex Wight & Arn. 46 Suksathan THAI PARNASSIA AND THREATS TO THEM Parnassia siamensis is characterised by having petals with shortly fimbriate mar- In Thailand, three Parnassia species gins, and candelabriform staminodes. How- have been recorded. ever, both characters seem to be very vari- able, suggesting that the species is probably 1. Parnassia mysorensis Heyne ex Wight conspecific with P. mysorensis . Further & Arn., Prodr. Fl. Ind. Orient. 35. 1834. studies are needed before the status of this (Figs. 1A, 2A–B). species is made. A widespread species, ranging from N Habitat: Limestone crevices in open limestone India (Sikkim) to S China and N Thailand. scrub near summit of Doi Chiang Dao, The species is characterised by having Chiang Mai province, 2220 m alt. tri-lobed staminodes. However, large Distribution: NORTHERN: Chiang Mai variation of staminode shape in Thai (Chiang Dao district, Doi Chiang Dao). plants has been observed. Threats: Small population, less than 50 Habitat: Open mountain ridges between plants have been observed. Invasive weed, 1500–2220 m alt. Eupatorium adenophorum Spreng. and for- Distribution: NORTHERN: Mae Hong Son est fire are the most serious threats in this (Muang district, Doi Pui), Chiang Mai area. (Chom Thong district, Doi Pa Kao, Doi Hua Specimens examined: Suksathan sn. (QBG). Suea, Doi Song Mea), Chiang Rai (Wiang Pha Pao district, Doi Phe Pan Nam-Doi Hua 3. Parnassia wightiana Wall. ex Wight & mot), and Phitsanulok (Chattrakaan district, Arn., Prodr. Fl. Ind. Orient. 35. 1834. (Fig. 1C). Phu Soi Dao). Threats: A serious forest-fire in 2007 A clearly distinct species characterised completely destroyed at least two populations by having proximally long fimbriate petal of P. mysorensis at Doi Inthanon and Khun Jae margins and five-lobed staminodes. It is the national parks. most widespread species, ranging from Specimens examined : Garrett 702 (BKF); India to S China and N Thailand. Suksathan 2809 (QBG), 2873 (QBG), 3057 (QBG), 3585 (QBG), 3592 (QBG), 4615 Habitat: Bog areas among open pine- (QBG); Watthana, Suksathan & Argent 584 dipterocarp forest at Ban Bo Luang, Chiang (E, QBG), 638 (E, QBG). Mai province. Distribution: Chiang Mai (Om Koi district, 2. Parnassia siamensis Shimizu, Acta Bo Luang tableland) Phytotax. Geobot. 24: 41. 1969. (Fig. 1B). Threats: Only three collections were made in the same area in 1969, 1973, and 1980. This species is known only from the Intensive searches for the plant took place type locality at Doi Chiang Dao, Chiang Mai. at the same locality in 2001, 2004, and 2007, Thai Parnassia and threats to them. 47 and not a single plant was found. Water- Specimens examined: Beusekom & Phengklai buffalos are the most serious threat in the 2251 (BKF); Shimizu et al. T-19039 (BKF); area. However, it cannot be denied that col- Smitinand 11846 (BKF). lection of plants for herbarium specimens has also imposed an increasing threat. Figure 2. Parnassia mysorensis Heyne ex Wight & Arn. A. natural habitat, open sandstone area at 2,100 m alt., Phu Soi Dao, Phitsanulok province; B. flowers and fruits, same locality. 48 Suksathan ACKNOWLEDGEMENTS Cronquist, A. 1981. The integrated system of classification of flowering plants. Co- I am grateful to Prof. Kai Larsen and lumbia University Press, New York. Dr. Anders Barford for their kind assistance. Gray, S.F. 1821. Parnassieae. A Natural Arrangement of British Plants 2: 623. I wish to thank the curators and staff of Gu, C. & Hultgård, U.M. 2001. Parnassia L. BKF, K, KUN and QBG herbaria for making (Saxifragaceae) . In: Flora of China. Z.Y. material available for study. Wu & P.H. Raven (Eds), vol. 8, pp. 358–379. Hallier, H. 1901. Über die Verwandtschaftsverhältnisse REFERENCES der Tubifloren und Ebenalen den polyphyletischen Ursprung der APG II. 2003. 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