Contrasting water, dry matter and air contents distinguish orthophylls, sclerophylls and succophylls (leaf succulents)

Differences in leaf texture (hardness, thickness) distinguish orthophylls (soft leaves), sclerophylls (hard leaves) and (semi)succophylls (water-storing leaves). Texture is controlled by dry matter, water and air contents. Our aim was to a) identify the best index of succulence, b) assess how these three components vary with leaf type, and c) derive bounds for these properties among the four main leaf-texture classes. Eight contrasting species from the Namib Desert, South Africa were assessed for their leaf area (A), thickness (z), dry mass (D), saturated water content (Q), and relative volume of dry matter, water and air to derive various indices of leaf texture. Q/A (= QV•z), where QV is saturated water storage per unit volume of leaf, is an ideal index of succulence. Specific leaf area (SLA) is more suitable as an index of hardness (SLA-1 = D/A) but only among non-succulents. Rising leaf specific gravity among sclero-orthophylls is due to replacement of air by dry matter but water am..., Fieldwork Leaves were collected from eight species growing wild at Groenriviersond, 500 km north of Cape Town, South Africa (30º 51' S, 17º 34' E). The species were selected to cover the full range of textures among perennials at the study site [specific leaf area (SLA) ranged from 2 to 20 mm2 mg-1, Lamont and Lamont 2000]. They were Pteronia onobromoides (Asteraceae, shrub to 50 cm tall, hard-leaved), Salvia lanceolata (Lamiaceae, shrub to 1 m tall, soft-leaved), Eriocephalus africanus (Asteraceae, shrub to 1 m tall, soft-leaved), Stoeberia utilis (Aizoaceae, syn. Mesembryanthemaceae, ground creeper, succulent), Ruschia fugitans (Aizoacae, syn. Mesembryanthemaceae, ground creeper, large-leaved succulent), Zygophyllum morgsana (Zygophyllaceae, shrub to 50 cm, semi-succulent), Othonna cylindrica (Asteraceae, shrub to 40 cm, succulent) and Senecio aff. sarcoides (Asteraceae, undershrub, small-leaved succulent). Nomenclature is as given in Eccles et al. (1999) and, from hereon, only the ge..., , # Data from: Contrasting water, dry matter and air contents distinguish orthophylls, sclerophylls and succophylls (leaf succulents) [https://doi.org/10.5061/dryad.ksn02v7g5](https://doi.org/10.5061/dryad.ksn02v7g5) ## Description of the data and file structure *Fieldwork* Leaves were collected from eight species growing wild at Groenriviersond, 500 km north of Cape Town, South Africa (30º 51' S, 17º 34' E). The species were selected to cover the full range of textures among perennials at the study site [specific leaf area (SLA) ranged from 2 to 20 mm2 mg-1, Lamont and Lamont 2000]. They were *Pteronia onobromoides* (Asteraceae, shrub to 50 cm tall, hard-leaved), *Salvia lanceolata* (Lamiaceae, shrub to 1 m tall, soft-leaved), *Eriocephalus africanus* (Asteraceae, shrub to 1 m tall, soft-leaved), *Stoeberia utilis* (Aizoaceae, syn. Mesembryanthemaceae, ground creeper, succulent), *Ruschia fugitans* (Aizoacae, syn. Mesembryanthemaceae, ground creeper, large-leaved succulent), *Zygophy...,叶片质地（硬度、厚度）的差异可区分软质叶（orthophylls）、硬质叶（sclerophylls）以及（半）肉质叶（(semi)succophylls，储水叶）。叶片质地由干物质、水分与空气含量共同调控。本研究旨在达成三个目标：a）确定最优的肉质性评价指标；b）解析干物质、水分、空气这三种组分随叶片类型的变化规律；c）明确四类主要叶片质地类群中各性状的取值范围。本研究选取南非纳米布沙漠的8个代表性物种，测定其叶面积（A）、叶片厚度（z）、干质量（D）、饱和含水量（Q）以及干物质、水分和空气的相对体积，以此计算多种叶片质地相关指标。Q/A（即QV·z，其中QV为单位体积叶片的饱和储水量）是理想的肉质性指标。比叶面积（specific leaf area, SLA）可作为硬度的评价指标（SLA⁻¹ = D/A），但该结论仅适用于非肉质植物。硬-软质叶类群的叶片比重上升，源于干物质取代了空气组分，但水分（原文此处未完成）... 野外采样： 本研究于南非开普敦以北500公里的Groenriviersond（南纬30°51′，东经17°34′）采集8种野生植物的叶片。所选物种覆盖了研究区域多年生植物的全部质地类型范围[比叶面积（SLA）范围为2~20 mm²·mg⁻¹，Lamont和Lamont 2000]。供试物种包括：*Pteronia onobromoides*（菊科，灌木，株高可达50 cm，硬叶）、*Salvia lanceolata*（唇形科，灌木，株高可达1 m，软叶）、*Eriocephalus africanus*（菊科，灌木，株高可达1 m，软叶）、*Stoeberia utilis*（番杏科，原隶属于日中花科，铺地草本，肉质）、*Ruschia fugitans*（番杏科，原隶属于日中花科，铺地草本，大叶肉质）、*Zygophyllum morgsana*（蒺藜科，灌木，株高可达50 cm，半肉质）、*Othonna cylindrica*（菊科，灌木，株高可达40 cm，肉质）以及*Senecio aff. sarcoides*（菊科，亚灌木，小叶肉质）。物种命名遵循Eccles等（1999）的标准，此后仅提及属名（原文此处未完成）。 # 数据集来源：水分、干物质与空气含量的差异可区分软质叶、硬质叶与肉质叶（叶肉质植物） [https://doi.org/10.5061/dryad.ksn02v7g5] ## 数据与文件结构说明 *野外采样* 本研究于南非开普敦以北500公里的Groenriviersond（南纬30°51′，东经17°34′）采集8种野生植物的叶片。所选物种覆盖了研究区域多年生植物的全部质地类型范围[比叶面积（SLA）范围为2~20 mm²·mg⁻¹，Lamont和Lamont 2000]。供试物种包括：*Pteronia onobromoides*（菊科，灌木，株高可达50 cm，硬叶）、*Salvia lanceolata*（唇形科，灌木，株高可达1 m，软叶）、*Eriocephalus africanus*（菊科，灌木，株高可达1 m，软叶）、*Stoeberia utilis*（番杏科，原隶属于日中花科，铺地草本，肉质）、*Ruschia fugitans*（番杏科，原隶属于日中花科，铺地草本，大叶肉质）、*Zygophy...（原文此处未完成）