Botanical Studies (2010) 51: 531-536.
Phacellanthus (Orobanchaceae), a newly recorded genus
in Taiwan
Shih-Wen CHUNG1, Tian-Chuan HSU1, and Ching-I PENG2 *
1 Division of Forestry Biology, Taiwan Forestry Research Institute, 53 Nanhai Rd., Taipei 100, Taiwan
2Herbarium (HAST), Biodiversity Research Center, Academia Sinica, Nangang, Taipei 115, Taiwan
(Received January 10, 2009; Accepted April 22, 2010)
ABSTRACT. A heretofore unrecorded holoparasite Phacellanthus tubiflorus Siebold & Zucc. (Orobanchaceae) was recently discovered in Taiwan. It represents a new genus for the island and is distinguishable from related holoparasitic taxa such as Aeginetia, Christisonia, Boschniakia, and Orobanche by a combination of charac­ters: stems with many scale-like leaves, inflorescence subcapitate or subcorymbose with 4-6 flowers, corolla white, and elongate, slender corolla-tube. Phacellanthus tubiflorus is rare on Taiwan, with no more than two dozen individuals occurring in the cloud zone of a mixed Chamaecyparis/broadleaved forest at 1,800-2,000 m elevation. This paper provides a taxonomic account of Phacellanthus and illustrations to aid in identification.
Keywords: Holoparasitic plant; New Record; Orobanchaceae; Phacellanthus tubiflorus; Rare plant; Taiwan.
INTRODUCTION
when the Flora of Taiwan (Yang and Lu, 1998; Boufford et al., 2003) was published. Since the completion of the six volumes of the Flora of Taiwan, 2nd edition, many ad­ditional genera, unknown from Taiwan at the time, have been discovered, e.g. Lomatogonium (Gentianaceae; Chen and Wang, 2000), Thismia (Burmanniaceae; Yang et al., 2002), Saccolabiopsis (Orchidaceae; Chung et al., 2006), Phryma (Phrymaceae; Jung et al., 2005), and Chikusichloa (Poaceae; Jung et al., 2007). Such discoveries provide evi­dence for the importance of sustained inventory in areas not easily accessible or rarely botanized.
Phacellanthus (Orobanchaceae) comprises a single ho-loparasitic species, P. tubiflorus Siebold & Zucc., distrib­uted in eastern China, Japan, Korea, and Russia (Tuyama, 1947; Zhang and Tzvelev, 1998). During one of our recent botanical surveys, P. tubiflorus was discovered in the northern part of the Central Mountain Range in northeast­ern Taiwan. Our collection represents the first discovery for both the genus and species for Taiwan, and a southern range extension from Japan. We hereby provide a taxo-nomic account of this rare species, which was unknown
Key to holoparasitic species of Orobanchaceae in Taiwan
1. Calyx spathe-like; pedicels more than 5 cm long.......................................................................................Aeginetia indica
1. Calyx absent or 5-lobed, not spathe-like; pedicels less than 2 cm long.
2. Stems usually above ground; inflorescence spicate or racemose, borne well above soil surface.
3. Plants villose; lower lip of corolla subequal to upper lip; stamens included in corolla.......Orobanche coerulescens
3. Plants glabrous; lower lip of corolla much shorter than upper lip; stamens exserted from corolla.............................
                     ................................................................................................................................................ Boschniakia himalaica
2. Stems usually underground; inflorescence subcapitate or subcorymbose, near soil surface.
4. Calyx absent; corolla tube 2.8-3.2 cm long, 2.5-3 mm across; fertile stamens 4..................Phacellanthus tubiflorus
4. Calyx lobes 5, persistent; corolla tube 4-6 cm long, 4-5 mm across; fertile stamens 2...............Christisonia hookeri
*Corresponding author: E-mail: bopeng@sinica.edu.tw.
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MATERIALS AND METHODS
Light microscopy
Fresh materials of Phacellanthus tubiflorus were collected from Taiwan. Voucher specimens have been preserved in the Herbarium of Taiwan Forestry Research
Institute (TAIF).
Samples were dissected and gradually dehydrated in an alcohol/tert-Butanol series, slowly infiltrated/embedded in paraffin, and then sectioned on a microtome. Sections (8 (im) were stained with Safranin O/Fast Green and examined/imaged on a Leica compound microscope.
Scanning election microscopy
Karyology
Samples were fixed in FAA (18:1:1―50% ethanol, gla­cial acetic acid, formalin). After dehydration in an alcohol-acetone series, samples were critical point dried, sputter coated with platinum, and observed under a scanning elec­tron microscope with an accelerating voltage of 18 kV.
Root tips were pretreated for 3-4 h in a mixture of 70 ppm cycloheximide and 250 ppm 8-hydroxyquinoline (1:1) at 18-20°C. They were then fixed for 1-3 h in a mixture of 45% acetic acid and absolute ethanol (1:3) at about 20°C, then preserved in 70% ethanol at 4°C. They
Figure 1. Phacellanthus tubiflorus. A, Habit; B, Inflorescence; C, Flower, dissected; D, Pistil, upper portion; E, Stamens; F, Capsules; G, Seed; H, Corolla and ovary, cross section showing parietal plancentation.
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533
were macerated for 1-3 min in 1 M HCL at 60°C, washed for 10 s, and then digested for 1-2 h in 4% pectinase. Finally, the root tips were squashed in modified Sharma's solution (Sharma, 1982). Chromosome spreads were observed under a Leica compound microscope.
Herbs, perennial, holoparasitic. Stem terete, glabrescent, solitary, unbranched, 4-8 cm long. Leaves scale-like, spirally arranged, ovate to ovate-triangular, involute, margin slightly membranous, apex acute or obtuse, 5-20 mm long, glabrous. Inflorescence subcapitate or subcorymbose, 4-6-flowered. Bracts scale-like, elliptic, entire or fringed, apex rounded, white, 20-25 mm long, 7-12 mm wide, glabrous. Corolla white, tubular, bilabiate, usually curved, glabrous; tube slender, 28-32 mm long, 2.5-3 mm across; upper lip orbicular, ca. 4 mm long; lower lip ca. 3 mm long, deeply 3-lobed, lobes elliptic, obtuse. Stamens 4, included, adnate to lower half of corolla tube, 10-16 mm long, glabrous, anthers ovate, ca. 1 mm long, 2-locular. Style filiform, 10-20 mm long, glabrous. Ovary superior, ellipsoid-globose, ca. 4 mm long; placentas 4,
Species description
phacellanthus tubiflorus Siebold & Zucc., Abh. Mat -
Phys. Baier. Akad. Wiss. 4(3): 142. 1846; Zhang and
Tzvelev, Fl. China 18: 243. 1998; Wu and Raven, Fl. China Illstr. 18: 267. f. 267. 2000.黃筒花 Figures 1, 2
Phacellanthus continentalis Komarov, Bull. Acad. Sci.
URSS 7: 267, f. 1-4. 1930. Tienmuia triandra Hu, Bull. Fan. Mem. Inst. Biol. Bot. 9: 6. 1939.
Figure 2. Phacellanthus tubiflorus. A, Habit and habitat; B, Root; C, Flowering individual; D, Fruiting individual; E, Habit and fruits; F, seed; G, H, Pollen SEM microphotographs. Scale bar equals 1 cm in A-E and 200 um in F-H.
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parietal; ovules numerous. Capsule ellipsoid, apex acute, ca. 7 mm long, 4 mm across, glabrous; style persistent. Seeds minute, ovoid, testa reticulate.
Distribution. Russia (Far East), China (Gansu, Hubei, Hunan, Jilin, Shaanxi, Zhejiang), Japan, Korea (Zhang and Tzvelev, 1998). Our collection represents a new record for both the genus and the species in Taiwan, and a southern range extension (Figure 3).
Specimen examined. TAIWAN. Ilan Co., Tatong Township, Taipingshan, Santieh Waterfall. 5 June 2005, S. W. Chung and T. C. Hsu 9897 (TAIF).
Phenology. Flowering in early June; fruiting from June to July.
Habitat and ecology. Phacellanthus tubiflorus was recently discovered in the northern part of the Central Mountain Range in northeastern Taiwan. It occurs in the cloud zone in a mixed Chamaecyparis/broadleaved for­est at 1,800-2,000 m elevation and is apparently very rare (Figure 4). No more than two dozen individuals were found on slopes and along trails. In addition to its rarity, Phacellanthus may have escaped attention because of its small size, seasonality, resemblance to a fungus and spe­cific microhabitat requirements. The host of the parasite in Taiwan is Machilus pseudolongifolia, Fraxinus spp. on the Chinese mainland (Zhang and Tzvelev, 1998) and Ulmus lacinata, Cornus contro^ersa, Morus bombycis, Kalopanax ricinifolium and Picrasma quassioides in Japan (Matsuura and Toyohuku, 1937) have also been reported as hosts.
Pollen and seed morphology. Pollen tricolpate, sub-globose, 300-310 jam in polar axis and 320-330 fim in equatorial diameter (Figure 2G, H). Seed ovoid, testa re­ticulate (Figure 2F).
Floral anatomy. Inflorescence 4- to 6-flowered; ovary unilocular with 4 parietal placentas; ovules numerous (Fig­ure 5).
Chromosome number. Cytological examination of so­matic chromosomes of Phacellanthus tubiflorus in Taiwan revealed 2n = 42 (Figure 6). Gametic chromosome num­bers of n = 19, 21, 26, 35, 38, 39 and 42 were reported for various populations from Japan (Matsuura and Toyohuku, 1937). Phacellanthus tubiflorus appears to be highly poly­morphic karyologically.
Morphological Notes. The morphology of the plants in Taiwan does not conform well to descriptions of Phacel-lanthus tubiflorus from mainland China (Zhang and Tzvelev, 1998) and Japan (Yamazaki, 2003). Yamazaki (2003) described the Japanese plants as having densely pu-berulent stems, but the stems of the plants from Taiwan are
Figure 4. Distribution and altitudinal maps of Phacellanthus tubiflorus (•) in Taiwan.
Figure 3. Global distribution of the genus Phacellanthus (Asia, Figure 5. Phacellanthus tubiflorus. Inflorescence, cross section. in shade). lf = Leaf; co = Corolla; oa = Ovary; ou = Ovules.
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Committee of the Flora of Taiwan, 2nd edition (eds.), Flora of Taiwan 2nd ed. Vol. 6. Dept. Bot., Natl. Taiwan Univ., Taipei, pp. 15-139.
Chen, C.H. and J.C. Wang. 2000. Lomatogonium chilaiensis (Gentianaceae), a newly recorded genus and new species in
Taiwan. Bot. Bull. Acad. Sin. 41: 323-326.
Chung, S.W., T.C. Hsu, and T. Yukawa. 2006. Saccolabiopsis taiwaniana (Orchidaceae), a new species from the Taiwan. Quart. J. Forest Res. 28: 25-28.
Matsuura, H. and T. Toyohuku. 1937. Karyological polymor­phism of Phacellanthus tubiflorus Sieb. et Zucc. Jap. J.
Genet. 13: 21-30.
Jung, M.J., G.I. Liao, and C.S. Kuoh. 2005. Phryma leptos-tachya (Phrymaceae), a new family record in Taiwan. Bot.
Bull. Acad. Sin. 46: 239-244.
Jung, M.-J. and C.-S. Kuoh. 2007. Chikusichloa Koidz. (Poace­ae), a newly recorded genus in the flora of Taiwan. Taiwania 52(3): 243-246.
Sharma, H.C. 1982. A technique for somatic counts from root tips of cereal seedings raised by embryo culture. Curr. Sci.
51: 143-144.
Tuyama, T. 1947. On the genus Phacellanthus of estern Asia. J. Jap. Bot. 21(7-12): 131-136.
Yang, S.Z., M.K. Richard, M.K. Saunders, and C.J. Hsu. 2002.
Thismia taiwanensis sp. nov. (Burmanniaceae tribe Thi-smieae): first record for the tribe in China. Syst. Bot. 27:
485-488.
Yang, Y.P. and S.Y. Lu. 1998. Orobanchaceae. In T. C. Huang et al. (eds.), Flora of Taiwan 2nd edn. Vol. 4. Editorial Com­mittee of the Flora of Taiwan, Dept. Bot., Natl. Taiwan Univ., Taipei, pp. 713-717.
Yamazaki, T. 2003. Orobanchaceae. In K. Iwatsuki et al. (eds.), Flora of Japan IIIa, Kodansha Ltd., Tokyo, pp. 381-383.
Zhang, Z.Y. and N.N. Tzvelev. 1998. Orobanchaceae. In Z. Y. Wu and P. H. Raven (eds.), Flora of China vol. 18, Scroph-ulariaceae through Gesneriaceae. Science Press (Beijing) and Missouri Botanical Garden (St. Louis), pp. 229-243.
Figure 6. Phacellanthus tubiflorus. Somatic chromosomes at metaphase, 2n = 42.
glabrous. The stamen filaments are sparsely pubescent ba-sally in mainland plants (Zhang and Tzvelev, 1998) while they are glabrous in Taiwan. Considering the diversity of chromosome numbers and the wide geographic distribu­tion of P. tubiflorus in Asia (Takasi, 1947), we are inclined to treat the plants from Taiwan as conspecific.
Acknowledgements. We thank Mr. Sheng-Kun Yu for field assistance and Ming-Jer Jung and Shin-Ming Ku for improving the manuscript.
LITERATURE CITED
Boufford, D.E., H. Ohashi, T.C. Huang, C.F. Hsieh, J.L. Tsai, K.C. Yang, C.-I Peng, C.S. Kuoh, and A. Hsiao. 2003.
A checklist of the vascular plants of Taiwan. In Editorial
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台灣新記錄屬植物：黃筒花屬
鐘詩文1 許天銓1 彭鏡毅2
1行政院農業委員會林業試驗所森林生物組
2中央研究院生物多樣性研究中心植物標本館（HAST)
本文描述台灣新記錄之列當科寄生植物黃筒花(Phacellanthus tubiflorus Siebold & Zucc.)；黃筒花屬
(Phacellanthus)亦為台灣之新記錄屬。本文並報導其花部解剖及種子、花粉顯微構造與染色體數（2n =
42)。黃筒花之族群發現於台灣東北部中海拔針闊葉樹混合林，其植株密被多數鱗狀葉，花序繖房狀，
花4-6朵，白色，花筒細長管狀，而與台灣列當科其他全寄生植物如：野菰屬(Aeginetia)，草蓰蓉屬
(Boschniakia)，假野菰屬(Cistanche)和列當屬(Orobanche)容易區別。
關鍵詞：全寄生植物；新記錄屬；列當科；黃筒花屬；黃筒花；稀有植物；台灣。