Roots, Stems, and Leaves Notes for Biology 2410* at Utah State University *Plants and fungi: ecosystem essentials

Life before reproduction Reproduction is essential to a species’ success Plants have to grow to the point that they are mature enough, and healthy enough, to reproduce. Roots, stems, and leaves are the workhorse structures of plants.

Roots Obtain water and dissolved nutrients from soil and mycorrhyzae Anchor plant Are point of contact for mycorrhizal fungi

Types of roots Primary root - from embryo Aerial root Primary root - from embryo Secondary roots –from primary root Adventitious roots –from leaf nodes May be modified for support or defense or … Adventitous roots

Root structures Tap roots – from primary root Fibrous roots – from adventitious or secondary roots Tuberous roots – thickened ROOTS Tubers are thickened stems Tuberous root Stem, not root http://www.museums.org.za/bio/images/enb7/enb07429x_beetroot.jpg http://trc.ucdavis.edu/egsutter/plb171/VisualMaterial/largePhotoSStruc/TubersPic/tuber-potato99lable.jpg

Rhizomes: underground stems, not roots Rhizomes have nodes and reduced leaves Rhizomes often root at nodes Rhizomes enable a plant to spread and reproduce Rhizomes are most common in mesic and wet habitats