All students of xylem structure-function relations need to be familiar with the work of Sherwin Carlquist. He studies xylem through the lens of the comparative method, which uses the appearance of similar anatomical features under similar conditions of natural selection to infer function. "Function" in biology implies adaptation; maximally supported adaptation inferences require experimental and comparative xylem scientists to work with one another. Engaging with comparative inferences of xylem function will, more likely sooner rather than later, bring one to the work of Sherwin Carlquist. To mark his 90th birthday, I highlight just a few examples of his extraordinarily perceptive and general comparative insights. One is "Carlquist's Law", the pervasive tendency for vessels to be solitary when background cells are conductive. I cover his pioneering of "ecological" wood anatomy, viewing xylem variation as reflecting the effects of selection across climate and habit variation. Another is the embolism vulnerability-conduit diameter relationship, one of the most widely invoked structure-function relationships in xylem biology. I discuss the inferential richness within the notion of Carlquistian paedomorphosis, including detailed functional inferences regarding ray cell orientation. My final example comes from his very recent work offering the first satisfactory hypothesis accounting for the geographical and histological distribution of scalariform perforation plates as an adaptation, including "Carlquist's Ratchet", why scalariform plates are adaptive but do not re-evolve once lost. This extraordinarily rich production over six decades is filled with comparative inferences that should keep students of xylem function busy testing for decades to come.

中文翻译：

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从卡尔奎斯特的生态木材解剖学到卡尔奎斯特定律：为什么比较解剖学对功能木质部生物学至关重要

所有学习木质结构-功能关系的学生都需要熟悉 Sherwin Carlquist 的工作。他通过比较法的视角研究木质部，比较法是利用相似的自然选择条件下相似解剖特征的外观来推断功能。生物学中的“功能”意味着适应；最大程度支持的适应推断需要实验和比较木质部科学家相互合作。参与木质部功能的比较推论，更有可能迟早将其带入舍温·卡尔奎斯特 (Sherwin Carlquist) 的工作中。为了纪念他的 90 岁生日，我仅举几个例子，说明他具有非凡的洞察力和普遍的比较洞察力。一个是“卡尔奎斯特定律”，当背景细胞具有导电性时，血管普遍趋于孤立。我介绍了他的“生态”木材解剖学先驱，将木质部变异视为反映了跨气候和习性变异的选择影响。另一个是栓塞脆弱性-导管直径关系，这是木质部生物学中应用最广泛的结构-功能关系之一。我讨论了 Carlquistian paedomorphosis 概念中的推理丰富性，包括关于射线细胞方向的详细功能推理。我的最后一个例子来自他最近的工作，该工作提供了第一个令人满意的假设，解释了标状穿孔板的地理和组织学分布作为改编，包括“Carlquist's Ratchet”，为什么标板是适应性的，但一旦丢失就不会重新进化。这份长达 60 年的异常丰富的作品充满了比较推论，应该让木质部功能的学生在未来几十年忙于测试。