Top grass radical - the indexing component, contracted form of 艸/草 used as a top-cap. Marks 萝 as a plant name. Almost every word for a vine, herb or vegetable wears this hat: 萝卜 (radish), 茄 (eggplant), 菜 (vegetable), 葡萄 (grape).
Bottom 罗 supplies the sound luó exactly. Simplified from traditional 蘿 with phonetic 羅 (net/silk-net). 罗 also appears in 萝卜 (luóbo, radish) - a common kitchen word that anchors the reading.
