Context: In the dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium. By the formation of a layer of cambium between the bundles (interfascicular cambium), a complete ring is formed, and a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside. The soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings.

Question: What shape are the bundles in the young stem of dicotyledons arranged in?
Answer: an open ring

Question: What does the cambium separate?
Answer: xylem and phloem

Question: What is a layer of meristem or formative tissue known as?
Answer: cambium

Question: What results from the development of xylem on the inside and phloem on the outside?
Answer: increase in thickness

Question: What's another name for the concentric rings in trees?
Answer: annual rings

Question: What is formed  when a layer of dicotyledons is formed between the bundles?
Answer: Unanswerable

Question: What causes a regular increase in young stems?
Answer: Unanswerable

Question: What happens when the annual rings are crushed?
Answer: Unanswerable

Question: How is soft phloem marked for each growth season?
Answer: Unanswerable

Question: How are bundles in young stems arranged in branches?
Answer: Unanswerable