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midrib 【植物;植物學】葉的中脈。

midriff

Leaves tufted ; stipes 15 - 30 cm long , densely scaly at base , glabrous above ; sterile lamina about 60 cm long and 20 cm wide , simply pinnate ; pinnae numerous , alternate or subopposite , linear - lanceolate , the largest about 12 cm long and 1 cm wide , base cordate , apex acuminate , margin finely toothed ; veins close , forking once or twice and forming areoles near the midrib ; fertile lamina similar to sterile ones , but somewhat reduced , about 8 cm long and 0 . 4 cm wide , lower surface almost entirely covered with sporangia 葉簇生;葉柄長15 - 30厘米,基部密被鱗片,向上近光滑;不育葉片長約60厘米,寬20厘米,一回羽狀;羽片多數,互生或近對生,線狀披針形,最長者長達12厘米,寬約1厘米,頂端長漸尖,基部心形,邊緣有細密鋸齒;葉脈1 - 2次分叉,近中脈形成網眼;能育葉與不育葉相似,但較小,長約8厘米,寬約0 . 4厘米,下部滿布孢子囊。

It is mainly characterized in the triangular - lanceolate leaves which are green but white with dark green reticulation along the midrib and more or less truncate at base ; the flowers are erect on the rachis and half - opened ; the lip is tripartite , glabrous , more or less urceolate in side view ; the hypochile is saccate , ovoid and big while the epichile is relatively tiny , reflexed , undivided and transversely oblong or subreniform 本種之主要特征為: ?呈三角?披針形, ?面?色,沿中?有白色斑塊, ?基多少呈截形;花直?于花軸,半張;唇瓣呈三段? ,平?無毛,側視時多少呈壺型;基段片囊? , ?形,巨大,先段片相對微小、反卷, ?再細?而呈橫向橢圓形。

Detail of young leaves and growing point ; many leaves reduced to bare midrib or narrow green corrugated residue of lamina ; youngest leaves and growing point brown and dead ; large green stipular lamina around crown 缺錳甘藍的“鞭尾癥:關鍵在于嫩葉和生長點,許多葉片露出中脈或縮小成綠色波狀的薄層殘留,心葉和生長點變褐并死亡,頂部周圍有大量綠色長有托葉的葉片。

Numerous small rounded dark brown or black necrotic patches in green leaves ; patches often in groups or rows close to midrib or major lateral veins , towards centre or basal areas of leaflects ; petioles green and healthy 缺錳的馬鈴薯葉片:葉片上有大量深褐色或黑色壞死小圓斑,葉的主脈或大部分側脈附近有條狀斑紋,向葉中部和基部擴散,葉柄正常并保持綠色。

As for the leaves , we use bezier curves to describe shape of leaf midrib . the texture image of leaf is embedded into the space of local frames along the midrib curve 對于葉片的生成,本文采用bezier參數曲線描述葉子中脈的形狀,把樹葉或草葉構成的星形結構紋理圖象嵌入到葉脈參數曲線的局部標架中來實現。

We use bezier curves to describe the shape of leaf midrib and embed the image of leaf into the space of local frames along the midrib curve 植物葉面的造型采用bezier參數曲線描述葉子中脈的形狀,然后將葉子的紋理圖象嵌入到葉脈曲線的局部標架中。

Severe “ whiptail ” condition in field specimen from and acid soil . bare midribs or very narrow residual lamina 甘藍缺鉬“鞭尾癥:在田間試驗和酸性土壤上有嚴重的鞭尾癥狀,中脈突出,狹小的葉片殘留。