Flos Campsis — Campsis grandiflora (Thunb.) Loisel. (family Bignoniaceae), the dried flower. The related American species Campsis radicans is traded and naturalised elsewhere.
Nature and flavour. Sweet and sour, cold. Liver and Pericardium systems.
A blood mover that is also classed as cooling, which makes it the one reached for when the stasis is described as having heat in it. The sources credit it with quickening the blood and breaking stasis, cooling the blood and dispelling wind, and record it for amenorrhoea with abdominal masses, for fixed stabbing pain, for itchy wind rashes, and — the use that gets quoted most — for the red nose and papules of what the texts call 酒齄鼻, applied as a wash as well as taken. That external application is the milder half of the record, and it is the half a modern reader is more likely to encounter. The traditional internal uses are recorded; the modern clinical evidence for them is limited and is not established.
性味归经。甘、酸，寒。归肝、心包经。
活血药中又归寒凉的一味，故在瘀而兼有热象的描述里最常被提到。古籍谓其破血祛瘀、凉血祛风；记载用于经闭癥瘕、固定刺痛、风疹瘙痒，以及被引用最多的一项 —— 古籍所称酒齄鼻的鼻赤与丘疹，既可内服亦可外洗。外用是这份记载中较温和的一半，也是现代读者更可能遇到的一半。上述传统内服用途有文献记载，其现代临床证据有限，尚未被证实。
这里最重的提示是古典的那一条：此花破血，古籍孕期直禁。孕妇或备孕者绝不可用；月经过多或有出血倾向者不宜；把它加到华法林或其它抗凝、抗血小板药上去，不是可以自行决定的事。另有一条属于物理性的提醒：多数人接触凌霄是从摆弄新鲜花开始，而非服用 —— 其近缘的美洲凌霄（Campsis radicans）有致接触性皮炎的文献记载，而凌霄属花朵的花粉与花蜜对眼睛和黏膜有刺激性，碰触或修剪时尤然。对园艺者而言戴手套、护眼是常规防护，这与干花入药的传统用途是两回事。同一中文名下流通着两个物种及不止一个药用部位，标准品为规定物种的干燥花。任何使用都须在合格执业者监督下进行；本页刻意不回答「该用多少」。