Branched alkanes have a lower biodegradability than unbranched alkanes. Plant hairs may be unicellular or multicellular, branched or unbranched. Their stems grow erect and are unbranched or sparsely branched. Furthermore, hemicelluloses are branched, whereas cellulose is unbranched. A medium size slender shrub reaching , often unbranched with reddish brown petioles. But "I. sanguinea" has unbranched stems, while "I. sibirica" has branched stems. The other genera have a pappus of simple unbranched hairs. It is branching or unbranched and hairy to hairless. Growing tall with unbranched stems, it is an herbaceous perennial. First, RhoA stimulates nucleation of unbranched actin filaments by activation of Diaphanous-related formins. It is the repeating unit in the skeleton of the unbranched alkanes. Stout and unbranched to thick stems. The flowering stems are erect and unbranched, high. Hollyhocks are annual, biennial, or perennial plants usually taking an erect, unbranched form. The Arecaceae (palms) have their leaves spirally arranged on an unbranched trunk.