倪静波,钮峥洋,3,郑锡荣,巫广民,童毅华
(1.中国科学院华南植物园,中国科学院植物资源保护与可持续利用重点实验室,广东 广州510650;2.中国科学院核心植物园,广东 广州510650;3.中国科学院大学,北京100049;4.广宁县林业局,广东 广宁526300)
簕竹属(BambusaSchreber)隶属于禾本科(Poaceae)竹亚科(Bambusoideae)簕竹族(Bambuseae),是竹亚科中最大的属之一[1-4]。该属现有100余种,广泛分布于亚洲热带及亚热带地区,中国约产80种,主要分布于南部和西南部地区[1,5],其中以广东种类最多,共有69种[6-7]。簕竹属植物主要特征为常为大型乔木状竹类,地下茎合轴丛生,秆每节具多分枝,箨耳明显,两耳大小不相等,箨片常直立,假小穗单生或数枚簇生于花枝各节,每枚小穗具2至多朵小花,每朵小花具6枚雄蕊,3柱头[1,5]。
目前,簕竹属可分为簕竹亚属(subgen.Bambusa)、绿竹亚属(subgen.Dengdrocalamopsis)、箪竹亚属(subgen.Lingnania)和孝顺竹亚属(subgen.Leleba)等4个亚属。其中,孝顺竹亚属约有35种,其主要特征为秆基部的分枝不特化为刺,箨片基部宽占箨鞘顶宽的1/2~3/4,箨耳明显[1,5]。
在2017年和2018年分别前往广东省广宁县和怀集县进行竹类植物调查的过程中,我们发现了一种未曾记录过的竹种。该种分枝常自秆第8节至第9节开始,秆基部的分枝不特化为刺,箨片基部宽占箨鞘顶宽的3/5~4/5,箨耳明显,显系簕竹属孝顺竹亚属的成员。后经过与近似种的比对研究后发现,本种实为一个未被描述过的新种,因此在这里予以发表。
绥江青竹 新种(图1-2)
图1 绥江青竹Fig.1 Bambusa suijiangensis J.B.Ni,Z.Y.Niu&Y.H.Tong
图2 绥江青竹Fig.2 Bambusa suijiangensis J.B.Ni,Z.Y.Niu&Y.H.Tong
Bambusa suijiangensis J.B.Ni,Z.Y.Niu&Y.H.Tong,sp.nov.(Figs.1-2)
Diagnosis:Bambusa suijiangensisis morphologically similar toB.albolineataL.C.Chia,but differs from it in basal part of culm being straight and without stripes,culm leaf with larger and obviously wavy auricles,and longer lemmas and anthers.
Arborescent bamboo.Rhizome pachymorph,short-necked.Culms erect,8-12 m tall and 5-6 cm in diameter,apically drooping;internodes 40-60 cm long,green,initially thinly white powdery,glabrous;wall 4-6 mm thick;nodes flat,glabrous,basal nodes usually with a ring of gray-white silky hairs above sheath scar;sheath scars prominent,with persistent remains of sheath base.Culm buds broadly ovate.Branches developing from 8th to 9th nodes upwards,inclined at an angle of 45°-60°with the culm,several to many,clustered,the central one dominant.Culm leaf sheaths caducous,thickly leathery,rigid,(22-25)cm×(28.5-35)cm,basal and bi-lateral parts of abaxial surface sparsely stiffly dull brown strigose,glabrescent,apex broadly arched,slightly oblique and asymmetrical;auricles large,unequal,obviously wavy wrinkled,continuous with blades base,margin with dense ca 3 mm long brown setae,larger ones oblong,2-3 cm long and 0.5-1 cm wide,smaller ones elliptic,ca 1/2 size of larger ones;ligules 1-2 mm tall,serrulate,apex arched,shortly fimbriate with trichomes ca 1-4 mm long;blades erect,narrowly triangular,(10-12)cm×(7-9)cm,ca 1/2 as long as sheath proper,abaxially sparsely hispidulous,adaxially glabrous,base not or slightly narrowed and extending outward to join auricles,3/5-4/5 as wide as sheath apex,apex acuminate.Foliage leaves 7-12 per ultimate branch;sheaths glabrous;auricles falcate,2-3 mm long,oral setae 1-9 mm long;inner ligules truncate or slightly arched,0.5-2 mm tall,serrulate,glabrous;leaf blades lanceolate to linear lanceolate,papyraceous,(8-20)cm×(1-2)cm,apex acute,base subrounded to cuneate,abaxially densely pubescent,adaxially glabrous,secondary veins 5-7 pairs,transverse veins inconspicuous;petioles(1-3)cm×(1-2)mm,glabrous.Pseudospikelets sessile,usually 2-3 fasciculate at nodes of flowering branches and branchlets,linear-lanceolate,dull purple when fresh,bronze-colored when dry,(3-4.5)cm×(0.5-0.7)cm;prophylls broadly ovate,2-3 mm long,2-keeled,keels densely ciliolate towards tips;gemmiferous bracts 2-3,broadly ovate,2-10 mm long,glabrous,17-19-veined,apex acute and mucronate;florets 6-9,apical one sterile;rachilla segments flat,3-5 mm long,glabrous,apex enlarged.Empty glume(or sometimes sterile lemma)usually 1,broadly ovate,ca.10 mm,15-17-veined,glabrous,apex acute and mucronate;lemma elliptic,11-16 mm long,glabrous,21-veined,apex acute and mucronate;palea lanceolate,10-15 mm long,slightly shorter than lemma,2-keeled,keels glabrous,6-8-veined between keels and 4-veined on either side of keels,apex acute;lodicules 3,unequal,fleshy,white,margins long ciliate,anterior 2 oblique,subspatulate,ca 3 mm long,posterior 1 obovate-elliptic,ca 2 mm long.Stamen 6,filaments slender,white,greenish when young;anthers yellow,tinged with purple,ca 7-8.5 mm long,apex retuse;ovary broadly ovoid,ca 2 mm long,1-1.5 mm in diameter,apex thickened and hispidulous,base stalked;style ca 1 mm long,hispidulous;stigmas3,7.5-9 mm long,plumose.Mature caryopsis unknown.
Type:CHINA.Guangdong:Zhaoqing City,Guangning County,Kengkou Town,near Daliang Village,23°34′32″N,112°20′26″E,16 August 2017,N.H.Xia,J.B.Ni&X.R.Zheng B2017009(holotype:IBSC).
Additional specimen examined(paratypes):CHINA.Guangdong:Guangzhou City,South China Botanical Garden,bamboo garden,23°10′49″N,113°21′10″E,20m alt.,15 March 2018,J.B.Ni NJB001(IBSC);Zhaoqing City,Huaiji County,Aozai Town,near Xinjiao Village,23°48′50″N,112°14′13″E,54 m alt.,12 October 2018,Huaiji Expedition 441224181012018LY(IBSC).
乔木状竹类;地下茎合轴丛生;秆直立,高8~12 m,直径5~6 cm,尾稍下垂;节间圆筒形,长40~60 cm,绿色,幼时略被白粉,无毛,秆壁厚4~6 mm;秆环平坦,无毛,基部的节常于箨痕之上方环生一圈灰白色绢毛;箨痕隆起,常留有残存的箨鞘基部;秆芽宽卵形;分枝常自秆第8节至第9节开始,分枝角度为40°~60°,以数枝乃至多枝簇生,具1明显主枝。箨鞘早落,厚革质,硬而脆,长22~25 cm,宽28.5~35 cm,背面基部及两侧近边缘疏生暗棕色刺毛,老时易脱落变无毛,先端稍倾斜而呈不对称的宽拱形;箨耳大,不相等,具明显波状褶皱,与箨片基部直接相连,边缘密生长约3 mm的黄棕色繸毛,大耳长圆形,长2~3 cm,宽0.5~1 cm,小耳椭圆形,其大小约为大耳的一半;箨舌高1~2 mm,先端隆起,边缘齿裂,具长1~4 mm的流苏状短毛;箨片直立,狭三角形,长10~12 cm,宽7~9 cm,其长度约为箨鞘的1/2,背面疏生短硬毛,腹面无毛,先端渐尖,基部不收窄或稍作圆形收窄便向两侧外延与箨耳相连,箨片基部宽度约为箨鞘先端宽的3/5~4/5。末级枝具7~12叶;叶鞘无毛;叶耳发达,呈镰刀形,长2~3 mm,边缘具弯曲而呈放射状的繸毛,繸毛长1~9 mm;叶舌高0.5~2 mm,截平或微凸,边缘微齿裂;叶片披针形至线状披针形,纸质,长8~20 cm,宽1~2 cm,上面无毛,下面密生短柔毛,先端渐尖基部近圆形或楔形,次脉5~7对,小横脉不明显;叶柄长1~3 mm,宽1~2 mm,无毛。假小穗无柄,常以2~3枚簇生于花枝及小枝各节,鲜时暗紫色,干时古铜色,线状披针形,长3~4.5 cm,宽0.5~0.7 cm;先出叶宽卵形,长2~3 mm,具2脊,脊上密被短纤毛;具芽苞片2~3,宽卵形,长2~10 mm,无毛,具17~19脉,先端急尖具短尖头;每枚小穗含小花6~9朵,顶端1小花不孕;小穗轴节间扁平,长3~5 mm,无毛,先端膨大;颖(或有时为不育外稃)常1,宽卵形,长约10 mm,无毛,具15~17脉,先端急尖具短尖头;外稃椭圆形,长11~16 mm,无毛,具21脉,先端急尖具短尖头;内稃披针形,长10~15 mm,稍短于外稃,具2脊,脊上无毛,脊间6~8脉,脊外每边各4脉,先端急尖;鳞被3,不相等,肉质,白色,边缘被长纤毛,前方2枚偏斜,近匙形,长约3 mm,后方1枚倒卵状椭圆形,长约2 mm;雄蕊6枚,花丝细长,白色,幼时浅绿色,花药黄色略带紫色,长7~8.5 mm,先端微凹;子房宽卵球形,长约2 mm,直径1~1.5 mm,顶端增粗且被短硬毛,基部具子房柄,花柱长约1 mm,被短硬毛,柱头3,长7.5~9 mm,羽毛状。成熟颖果未见。
模式标本:广东肇庆市广宁县坑口镇大良村附近,23°34′32″N,112°20′26″E,2017年8月16日,夏念和、倪静波和郑锡荣B2017009(主模式,IBSC);广东广州市华南植物园竹园,23°10′49″N,113°21′10″E,海拔20 m,2018年3月15日,倪静波NJB001(副模式,IBSC);广东肇庆市怀集县坳仔镇新教村附近,23°48′50″N,112°14′13″E,海拔54 m,2018年10月12日,怀集普查队441224181012018LY(副模式,IBSC)
分布及生境:产广东怀集县、广宁县,常栽培于溪河边、村落附近,未见野生居群。
词源:种加词“suijiangensis”来源于“绥江”,因该种常见栽培于绥江流域。
用途:该种常用于编制各种竹器、竹缆、竹笠和工艺品等,也可用于制作香骨、香末燃料或造纸。
俗名:青竹(怀集)、蔑竹(怀集、广宁)。
讨论:该种与花竹(B.albolineataL.C.Chia)最为相近,两者均为大型乔木状竹类,箨鞘背面基部和近两侧边缘处疏生暗棕色刺毛,箨耳褶皱,箨片与箨鞘的长度比约为1/2,但区别在于该种秆基部挺直,节间无黄白色条纹,箨耳大,大耳(2~3)cm×(0.5~1)cm,小耳(0.9~1.6)cm×(0.4~0.7)cm,具明显的波状褶皱,外稃长11~16 mm,花药长7~8.5 mm,而花竹基部秆呈“之”字曲折,有黄白色纵条纹,箨耳小,大耳(1~1.4)cm×(0.5~0.7)cm,小耳(0.5~0.8)cm×(0.3~0.5)cm,仅具轻微的褶皱,外稃长7~9 mm,花药长约4 mm。两者的详细区别见表1。
表1 绥江青竹与花竹的形态比较Tab.1 The morphological comparison of Bambusa suijiangensis and B.albolineata