BIOL 2242 Lecture Notes - Lecture 20: Vascular Cambium, Ranunculus, Cucurbita

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2242
• Professor: Isobel Waters

Document Summary

Ranunculus (cid:523)buttercup(cid:524) lacks secondary development (cid:523)doesn"t produce vascular cambium) (fig. Herbaceous annual: closed bundles i. e. , lack vascular cambium. Cap plus bundle sheath of sclerenchyma fibres: as with all stems, endarch xylem and exarch phloem. Only metaphloem persists (sieve tubes and companion cells) Protoxylem to inside of bundles with vessels, lots of parenchyma. Vascular cambium between external phloem and metaxylem (open: lacks phloem fibre cap. Instead has zone perivascular fibres in cortex: sclerenchyma fibres. Vine, uses objects, other plants for support versus gravity. ** may ask based on cell what would plant potentially look like: metaxylem (and secondary xylem) has huge vessels, few tracheids. 25. 8c, p. 584: monocots (plus few eudicots) have bundles through ground tissues. Appear scattered but pattern is complex yet regular: no distinction between cortex and pith. 588: many bundles connect to many leaves. Differences between monocots & eudicot stems: atactostele arrangement of bundles. Eustele: ground tissue, not separated into cortex and pith.