趙佳敏 李孟凱 龐深深 鄭維列 邢震 周鵬 王偉
摘? 要:掌握區(qū)域本底植物資源特點(diǎn)對(duì)植物區(qū)系研究具有重要意義,蘭科植物是現(xiàn)存被子植物中最進(jìn)化的類(lèi)群,其分布調(diào)查及種群特點(diǎn)均是研究的重點(diǎn)。西藏為我國(guó)蘭科植物分布的熱點(diǎn)區(qū)域,尤其在世界第一大峽谷的雅魯藏布大峽谷區(qū)域,其蘭科植物本底資料尚不清楚,近年來(lái)有諸多新分布及新種陸續(xù)報(bào)道。為進(jìn)一步摸清雅魯藏布大峽谷區(qū)域的蘭科植物分布,西藏農(nóng)牧學(xué)院林學(xué)團(tuán)隊(duì)近年來(lái)多次進(jìn)入大峽谷核心區(qū)域進(jìn)行蘭科植物本底資源調(diào)查。經(jīng)鑒定,結(jié)果發(fā)現(xiàn)西藏蘭科植物分布新記錄種5個(gè):分別為石斛屬(Dendrobium)的獨(dú)龍石斛(Dendrobium praecintum)、具槽石斛(Dendrobium sulcatum)、球花石斛(Dendrobium thyrsiflorum);齒唇蘭屬(Odontochilus)的齒唇蘭(Odontochilus lanceolatus);菱蘭屬(Rhomboda)的白肋菱蘭(Rhomboda tokioi)。5個(gè)西藏蘭科植物新記錄種均發(fā)現(xiàn)于西藏自治區(qū)墨脫縣附近,其中獨(dú)龍石斛(D. praecintum)、具槽石斛(D. sulcatum)、球花石斛(D. thyrsiflorum)和齒唇蘭(D. tokioi)均為喜馬拉雅南麓的廣布種,本次發(fā)現(xiàn)地點(diǎn)在一定程度上印證了這4種蘭科植物在喜馬拉雅南麓錫金至云南段呈連續(xù)分布;白肋菱蘭(A. lanceolatus)則為我國(guó)新的分布點(diǎn)(之前報(bào)道見(jiàn)于廣東、臺(tái)灣等地)。因此,該研究結(jié)果對(duì)西藏蘭科植物區(qū)系及雅魯藏布大峽谷蘭科植物區(qū)系研究具有一定的意義。
關(guān)鍵詞:蘭科;新記錄種;西藏中圖分類(lèi)號(hào):Q949.71+8.43 ?????文獻(xiàn)標(biāo)識(shí)碼:A
Five Newly Recorded Species of Orchidaceae in Tibet
ZHAO Jiamin, LI Mengkai, PANG Shenshen, ZHENG Weilie, XING Zhen, ZHOU Peng, WANG Wei
Tibet Agriculture & Animal Husbandry University, Nyingchi, Tibet 860000, China
Abstract: The characteristics of regional background plant species are of great significance to the study of flora and plant species evolution. Orchids are the most evolved group of angiosperms, and the distribution and population characteristics have been focused for a long time. Tibet is a hot area of orchids distribution in China, especially in Yarlung Zangbo Grand Canyon, the worlds largest grand Canyon and where the background information of orchids is still unclear. As a result, many investigations have been carried out and lots of studies about newly records and new species of Orchidaceae have been reported in recent years. In order to understand Orchidaceae in Yarlung Zangbo Grand Canyon, the member of forestry Innovation Team of Xizang Agriculture and Animal Husbandry University have investigated the resources of orchids in the Grand Canyon for many times in recent years. After identification, 5 newly records species of orchidaceae were observed in Tibet, which wereDendrobium praecintum,Dendrobium sulcatum,Dendrobium thyrsiflorum,Odontochilus lanceolatus, andRhomboda tokioi. All of the five newly Tibetan records of orchids were founded in Modog County, Tibet Autonomous Region. In additon,D. praecintum, D. sulcatum,D. thyrsiflorumandD. tokioiare widely distributed in the southern of the Himalayas, but this study was the first report that the four species were existed in Tibet. Moreover, our results indicated that the four orchids maybe continuously distributed from Sikkim to Yunnan in the southern of the Himalayas to some extent. Additionally, the distribution area ofA. lanceolatusis a newly distributed site in China (previously reported in Guangdong, Taiwan, and so on). Therefore, our results have values for the diversity and floristic characteristics of orchids in Yarlung Zangbo Grand Canyon.
Keywords: Orchidaceae; newly recorded; Tibet
DOI: 10.3969/j.issn.1000-2561.2022.04.007
蘭科植物資源調(diào)查是掌握蘭科本底資料的基礎(chǔ),對(duì)研究蘭科植物的地理分布和資源多樣性具有重要意義[1]。青藏高原獨(dú)特的地理位置及氣候特點(diǎn)已逐漸成為蘭科植物調(diào)查的熱點(diǎn)區(qū)域[2-4]。近年來(lái),西藏蘭科植物新記錄種[5-8]、中國(guó)新記錄種[1, 9]及新種屢見(jiàn)報(bào)道[10-11],主要發(fā)現(xiàn)地點(diǎn)均為雅魯藏布大峽谷下游,尤其是西藏墨脫縣。為進(jìn)一步明確西藏蘭科植物本底資源,西藏農(nóng)牧學(xué)院林學(xué)團(tuán)隊(duì)在2020年3—12月開(kāi)展西藏自治區(qū)植物多樣性調(diào)查期間,對(duì)墨脫縣蘭科植物進(jìn)行了重點(diǎn)關(guān)注,后經(jīng)過(guò)鑒定及查閱文獻(xiàn)資料,發(fā)現(xiàn)西藏蘭科新記錄種5個(gè),分別為獨(dú)龍石斛(Dendrobium praecintum)、具槽石斛(Dendrobium?sulcatum)、球花石斛(Dendrobium?thyrsiflorum)、白肋菱蘭(Rhomboda tokioi)、齒唇蘭(Odontochilus?lanceolatus),現(xiàn)對(duì)這5個(gè)新記錄種植物進(jìn)行描述和報(bào)道。憑證標(biāo)本保存于西藏農(nóng)牧學(xué)院標(biāo)本館(TAAHUC?。?。
Dendrobium praecintumRchb.f.in Gard. Chron. n.s.7: 750. 1877.
附生植物,莖直徑2~3?mm,高達(dá)70?cm,近圓形;節(jié)間長(zhǎng)1.5~4.0?cm,上部分枝具葉;葉披針形,長(zhǎng)5~9?cm,寬0.7~12.0?cm;花序腋生,具1~4朵花,通常具2朵花,基部具管狀鞘;苞片卵形,長(zhǎng)約2?mm;花白色,邊緣粉紅色;花梗和子房長(zhǎng)約1?cm,中萼片披針形,側(cè)萼片鐮狀卵形,花瓣卵狀披針形,唇瓣3裂;中裂片長(zhǎng)圓形,先端鈍,邊緣具硬毛[12]。
花期:5—6月。
分布:西藏墨脫縣背崩鄉(xiāng)德?tīng)栘暣濉?/p>
憑證標(biāo)本:西藏自治區(qū)墨脫縣背崩鄉(xiāng),海拔1570 m的常綠闊葉林樹(shù)干上。王偉等,2019468,TAAAHUC!。
討論:本種與竹枝石斛(D. salaccense)植株形態(tài)相近,但其花特征差異較大,如前者花較大,萼片及花瓣具紅色斑塊,唇瓣3裂,先端具毛,因此,與竹枝石斛易于區(qū)分。
Dendrobium sulcatumLindley Edwardss Bot. Reg. 24: ad t. 65. 1838.
莖直立,長(zhǎng)24~28?cm,肉質(zhì),由基部向上逐漸增粗,具縱條紋和數(shù)個(gè)節(jié)直立;葉紙質(zhì),互生于莖的近頂端,長(zhǎng)圓形,長(zhǎng)18~21?cm,寬4.5?cm,先端急尖;總狀花序從當(dāng)年生具葉的莖上端發(fā)出,長(zhǎng)8~15?cm;花苞片很小,狹卵狀披針形,長(zhǎng)約5?mm;花質(zhì)地薄,奶黃色,花瓣近倒卵形,長(zhǎng)2.4?cm,寬1.1?cm,先端銳尖,基部收狹為短爪,具5條脈;藥帽前后壓扁的半球形或圓錐形,頂端稍凹,光滑,前端邊緣多少不整齊[13]。
花期:6月。
分布:西藏墨脫縣背崩鄉(xiāng)德?tīng)栘暣濉?/p>
憑證標(biāo)本:西藏自治區(qū)墨脫縣背崩鄉(xiāng),附生于海拔600?m的常綠闊葉林樹(shù)干上。王偉等,2020272,TAAAHUC!。
討論:本種具極扁的假鱗莖,唇瓣兜狀,因此,易與同組的近似種區(qū)分,如密花石斛(D.?densiflorum)。
Dendrobium thyrsiflorumH. G. Reichenbach ex André Ill. Hort. 22: 88. 1875.
莖直立或斜立,圓柱形,粗狀,長(zhǎng)12~46?cm,粗7~16?mm;總狀花序側(cè)生于帶有葉的老莖上端,下垂,長(zhǎng)10~16?cm,密生許多花,花序柄基部被3~4枚紙質(zhì)鞘;花苞片淺白色,倒卵形,長(zhǎng)10~ 15?mm,寬5~13?mm,先端圓鈍,具數(shù)條脈;花瓣近圓形,長(zhǎng)14?mm,寬12?mm,先端圓鈍,基部具長(zhǎng)約2?mm的爪,邊緣具不整齊的細(xì)齒;蕊柱足淡黃色,長(zhǎng)4?mm;藥帽白色[13]。
花期:4—5月。
分布:林芝市墨脫縣墨脫村附近。
憑證標(biāo)本:林芝市墨脫縣墨脫村附近,附生于海拔1280?m林中樹(shù)干上。王偉等,2019336,TAAAHUC!。
討論:本種易與密花石斛(D.?densiflorum)相混淆,主要區(qū)別在于后者的莖通常棒狀或紡錘形,具明顯的4個(gè)棱;萼片和花瓣淺黃色。
Anoectochilus lanceolatusLindl. , Gen. Sp. Orch. Pl. 499. 1840.
植株高15~30?cm;根狀莖伸長(zhǎng),節(jié)上生根;莖直立,圓柱形,無(wú)毛,具4~5枚葉;葉片卵形、卵狀披針形或橢圓形,長(zhǎng)1.5~8.0?cm,寬1~5?cm,上面暗綠色,中肋和2側(cè)的脈有時(shí)色較淺,背面淡綠色,先端急尖,基部寬楔形或圓鈍,斜歪,基部驟狹成柄;葉柄長(zhǎng)9~20?mm,下部擴(kuò)大成抱莖的鞘;總狀花序具3~10余朵花;花苞片披針形或卵狀披針形,先端漸尖;子房圓柱形,扭轉(zhuǎn),無(wú)毛,連花梗長(zhǎng)9~10?mm;花黃色,倒置(唇瓣位于下方);萼片黃綠色,無(wú)毛,具1脈;中萼片卵形或卵狀長(zhǎng)圓形,凹陷呈舟狀;側(cè)萼片張開(kāi),斜歪的卵狀橢圓形;花瓣帶白綠色,斜歪,半卵形,基部收狹,上部驟狹成細(xì)長(zhǎng)的鈍頭,具1脈;唇瓣金黃色,呈“Y”字形,長(zhǎng)1.8~2.0?cm,基部略擴(kuò)大并凹陷呈圓球形,中部收狹成細(xì)、長(zhǎng)4~6?mm、其兩側(cè)各具4~7條流蘇狀裂條的爪,前部明顯擴(kuò)大并2裂,裂片楔狀長(zhǎng)圓形或倒卵形[14]。
花期:6—9月。
分布:西藏墨脫縣背崩鄉(xiāng)附近。
憑證標(biāo)本:西藏墨脫縣背崩鄉(xiāng),生長(zhǎng)于海拔790?m的闊葉林下。王偉等,2019074,TAAAHUC!。
討論:本種與西南齒唇蘭(O. elwesii)和短柱齒唇蘭(O. brevistylis)相近,以苞片大而區(qū)分
于西南齒唇蘭,花為黃色且短于子房區(qū)分于短柱齒唇蘭。
Rhomboda tokioi (Fukuyama) Ormerod Austral. Orchid. Rev. 63(4): 11. 1998.
植株高15~28 cm;莖暗紅棕色,具4~6片葉;葉背面淡綠色,正面沿中脈有時(shí)具白色條紋,卵形到卵狀披針形;葉柄基部具管狀鞘1~3?cm;花梗5~15?cm,具1~4個(gè)不育苞片;花序軸3~6?cm,松散分布3~15花;花苞片帶褐色紅色,卵狀披針形;下部超過(guò)子房,邊緣具緣毛,先端漸尖;花半開(kāi),不倒立;子房和花梗7~10?mm,無(wú)毛到疏生短柔毛;萼片紅棕色,無(wú)毛到疏生短柔毛,具1脈;側(cè)萼片卵形,先端銳尖;花瓣白色,卵形,無(wú)毛,具1脈,先端銳尖;唇瓣白色,長(zhǎng)圓狀披針形;基部有2個(gè)大胼胝體;邊緣內(nèi)卷,先端鈍;花柱長(zhǎng)約1.5?mm[15]。
花期:9—10月。
分布:西藏墨脫縣德?tīng)栘暣甯浇?/p>
憑證標(biāo)本:西藏墨脫縣德?tīng)栘暣?,生長(zhǎng)于海拔1650?m的闊葉林下。王偉等,2019500,TAAAHUC!。
討論:本種與小片菱蘭(R. abbreviata)相近,無(wú)花極易混淆,主要區(qū)別前者唇瓣狹長(zhǎng)圓狀披針形,不同于后者的唇瓣先端二叉分裂。
本次發(fā)現(xiàn)的5個(gè)西藏新記錄種,其中獨(dú)龍石斛(D. praecintum)之前報(bào)道于云南與錫金,齒唇蘭(D. tokioi)廣布于我國(guó)南部,國(guó)外見(jiàn)于錫金、尼泊爾、印度東北部、緬甸、越南、泰國(guó),本次均發(fā)現(xiàn)于西藏墨脫,一定程度上表明這2個(gè)種在喜馬拉雅南麓云南至錫金段可能連續(xù)分布;具槽石斛(D. sulcatum)與球花石斛(D. thyrsiflorum)均為該區(qū)域廣布種,但具槽石斛之前在我國(guó)僅見(jiàn)于云南報(bào)道,本次為其在我國(guó)新的分布點(diǎn);白肋菱蘭(A. lanceolatus)之前報(bào)道見(jiàn)于我國(guó)廣東、臺(tái)灣及國(guó)外日本、越南等地海拔1500 m以下的林下,本次發(fā)現(xiàn)于墨脫縣海拔1650 m處,其垂直分布上限高于之前記錄。本研究結(jié)果補(bǔ)充了這5種蘭科植物在西藏記錄的空白,對(duì)西藏蘭科植物區(qū)系及雅魯藏布大峽谷蘭科植物區(qū)系研究具有一定的意義。
參考文獻(xiàn)