Complex sentence: The bright green cotyledons are and can be either convex or concave, measuring 1.6 to 2.2 cm long by 0.9 to 1.2 cm wide, and arise from a stocky seedling stem, known as the hypocotyl, which is reddish and covered in short hairs.
Split into simpler sentences: The bright green cotyledons are and can be either convex or concave, measuring 1.6 to 2.2 cm long by 0.9 to 1.2 cm wide. These arise from a stocky seedling stem, known as the hypocotyl, which is reddish and covered in short hairs.