22 Gymnosperms Overview

This set of flashcards reviews key concepts related to gymnosperms, including their characteristics, classification, and reproductive mechanisms.

What is the largest group of gymnosperms?

Conifers, which include 70 genera and approximately 630 species.

What are the main characteristics of conifer leaves?

They are needle-like, which contributed to their success during the Permian period.

What is Phylum Cycadophyta commonly known for?

It includes palm-like plants found in tropical and subtropical regions.

How many genera and species are currently classified under Cycadophyta?

11 genera with approximately 300 species.

What was the significance of cycads during the Mesozoic era?

They were hugely abundant and often referred to as the 'Age of Cycads and Dinosaurs'.

What is the name of the only cycad species native to the US?

Zamia integrifolia.

What type of roots do cycads possess?

Coralloid roots, which host the cyanobacterium Anabaena cycadeae.

What is the function of the cyanobacterium found in cycad roots?

It fixes atmospheric nitrogen.

How are cycads pollinated?

Most cycads are insect-pollinated, often associated with beetles.

What is unique about the Ginkgo biloba?

It is the only surviving species in Phylum Ginkgophyta and is deciduous.

What are the distinguishing features of Ginkgo leaves?

They are fan-shaped and can reach up to 30m tall.

Why are male Ginkgo trees preferred for urban plantings?

They produce seeds with a less offensive smell compared to female trees.

What is the main characteristic of the reproductive process in Ginkgo?

Fertilization may not occur until the ovules are shed.

What are the three genera in Phylum Gnetophyta?

Gnetum, Ephedra, and Welwitschia.

How do Gnetophyta plants resemble angiosperms?

They have angiosperm-like traits, and their strobili clusters resemble angiosperm inflorescences.

What is a notable morphological trait of Gnetophyta?

They exhibit huge variation in morphology despite being grouped together genetically.