Celtuse also called stem lettuce, celery lettuce, asparagus lettuce, or Chinese lettuce, IPA (UK,US) /ˈsɛlt.əs/, is a cultivar of lettuce

Lettuce

Lettuce is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important...

 grown primarily for its thick stem

Plant stem

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

, used as a vegetable

Vegetable

The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....

. It is especially popular in China, where it is the most common form of lettuce, and is called wosun or woju (although the latter name may also be used to mean lettuce in general).

The stem is usually harvested at a length of around 15–20 cm and a diameter of around 3–4 cm. It is crisp, moist, and mildly flavored, and typically prepared by slicing and then stir frying

Stir frying

Stir frying is an umbrella term used to describe two Chinese cooking techniques for preparing food in a wok: chǎo and bào . The term stir-fry was introduced into the English language by Buwei Yang Chao, in her book How to Cook and Eat in Chinese, to describe the chǎo technique...

with more strongly flavored ingredients.