Modifiers matching ornamental:

• southern,
• woody,
• low,
• tender,
• herbaceous,
• tropical,
• important,
• native,
• monocotyledonous,
• common,
• sensitive,
• outdoor,
• deciduous,
• unusual,
• popular,
• traditional,
• beautiful,
• exotic,
• noninvasive,
• perennial,
• small,

Simple categories matching monocotyledonous:

• plant,
• species,
• ornamental,
• grass,
• seed,