Secondary Growth and Other Adaptations (Video) - Vocabulary Flashcards

Vocabulary flashcards covering key terms related to secondary growth, vascular tissues, periderm, wood, bark, and tree-ring analysis from the video notes.

Apical meristem

The primary growth tissue at shoot and root tips that gives rise to the protoderm, ground meristem, and procambium (all other meristems originate from it).

Procambium

Primary meristem that differentiates into the primary vascular tissues, xylem and phloem.

Ground meristem

Primary meristem that forms ground tissue, including cortex and pith.

Protoderm

Primary meristem that gives rise to the epidermis.

Primary xylem

Xylem produced during primary growth from the procambium.

Primary phloem

Phloem produced during primary growth from the procambium.

Pith

Central ground tissue in the stem, derived from ground meristem; stores nutrients in many plants.

Cortex

Ground tissue between the epidermis and the vascular tissue.

Fascicular cambium

Part of the vascular cambium located inside each vascular bundle.

Interfascicular cambium

Part of the vascular cambium formed from dedifferentiated parenchyma between bundles, connecting to fascicular cambium.

Vascular cambium

Lateral meristem that forms secondary xylem (inside) and secondary phloem (outside), producing wood and bark.

Secondary xylem

Xylem formed by the vascular cambium during secondary growth; constitutes wood.

Secondary phloem

Phloem formed by the vascular cambium toward the outside during secondary growth.

Cork cambium

Lateral meristem that produces cork (phellem) and phelloderm; also called phellogen.

Phelloderm

Inner living layer produced by the cork cambium; part of the periderm.

Cork (phellem)

Outer protective tissue produced by the cork cambium; rich in suberin and water-impermeable.

Periderm

Protective tissue replacing the epidermis in woody plants; consists of cork cambium, cork, and phelloderm.

Lenticel

Porous regions in periderm with large intercellular spaces that allow gas exchange.

Suberin

Waxy, water-impermeable substance in cork cell walls that limits water loss.

Phellogen

Alternative name for cork cambium.

Heartwood

Central, older xylem that is often nonconductive and darker due to resins and other deposits.

Sapwood

Outer, younger xylem that conducts water.

Vascular rays

Radial files of parenchyma that transport materials and store substances between xylem and phloem.

Tree rings

Annual growth rings formed by seasonal variation in xylem production; reflect growth conditions.

Dendrochronology

Dating wood by analyzing tree-ring patterns and cross-dating living and ancient wood.

Cross-dating

Matching ring patterns from multiple trees to build a continuous chronology.

Early wood (Springwood)

Wood formed in spring; usually lighter, with larger vessels and lower density.

Late wood (Summerwood)

Wood formed later in the season; denser and darker due to smaller vessels and thicker walls.

Additive division

Periclinal division of vascular cambium that adds more xylem or phloem cells.

Multiplicative division

Anticlinal division of cambial initials that increases the number of cambial cells, expanding the ring.

Auxin (in secondary growth)

Plant hormone that promotes secondary xylem differentiation from the vascular cambium; transporter genes are expressed before differentiation.

Gibberellin (in secondary growth)

Hormone that promotes secondary phloem formation; auxin is also involved but in reduced amounts.