spermatophyte

seed plants

spermatophyte common name

\~285,000 species

spermatophyte worldwide diversity

\~3,500 species

spermatophyte alabama diversity

1. gymnosperm
2. angiosperm

two types of spermatophytes

tracheids only

gymnosperm xylem

both tracheids and vessel members

angiosperm xylem

sieve cells and albuminous cells

gymnosperm phloem

sieve members and companion cells

angiosperm phloem

the only plants that have sieve members and companion cells

characteristic of angiosperm phloem

protostele actinostele

gymnosperm and angiosperm dicot root stele

siphonostele eustele

angiosperm monocot root stele

siphonostele eustele with vascular cambium and secondary growth

gymnosperm and angiosperm dicot stem stele

atactostele with vascular cambium and secondary growth absent

angiosperm monocot stem stele

megaphyll

spermatophyte leaves

eusporangium

spermatophyte sporangia

pollen grain

microgametophyte

dehiscent sporangium

sporangium that opens to release pollen grains

indehiscent sporangium

sporangium that doesn’t open to release the megaspores

nucellus

megasporangium synonym

1. microsporangium is dehiscent
2. megasporangium is indehiscent

micro- and megaspore release mechanisms of spermatophytes

heterosporus

spore habit of spermatophytes

1. endosporic
2. nonphotosynthetic
3. unisexual

spermatophyte micro- and megagametophyte characteristics

pollen grain

spermatophyte microgametophyte synonym

4 cells

number of cells in a pollen grain

non-flagellated

spermatophyte sperm

is not required

water in spermatophyte syngamy

pollination

takes place in order for syngamy to occur without the need for water

1. pinophyta
2. magnoliophyta

alabama spermatophyte phyla

coniferophyta

pinophyta synonym

conifers

pinophyta common name

\~650 species

pinophyta worldwide diversity

1. most diverse gymnosperm phylum
2. world’s largest tracheophytes
3. world’s oldest tracheophytes

pinophyta key characteristics

\~12 species

pinophyta alabama diversity

only indigenous alabama gymnosperm phylum

alabama pinophyta key characteristic

sequoiadendron giganteum (giant redwood)

world’s largest tracheophyte

1. endemic to california
2. \~300+ feet tall

giant redwood key characteristics

pinus longavea (bristlecone pine)

oldest tracheophyte

1. endemic to the U.S. (california, nevada, utah
2. \~4,500+ years old

bristlecone pine key characteristics

1. pinus
2. juniperus
3. tsuga
4. taxodium

pinophyta representative genera

xeric forests

pinus habitat

xeric glades

juniperus habitat

mesic forests

tsuga habitat

cypress swamp

taxodium habitat

longleaf pines

dominant arborescent of southern pine forests

southern pine forests

largest mono-cultured arborescent biomes

only tracheids

pinus xylem

sieve cells and albuminous cells

pinus phloem

excurrent, brought about by apical dominance

pinus growth form

excurrent plant growth

growth pattern where the main stem of the plant continues to grow upward, while the lateral branches grow out from the sides, resulting in a conical or pyramidal shape

apical dominance

phenomenon in plants where the main, central stem of the plant is dominant over its lateral branches due to the production of auxin hormone in the apical meristem, which inhibits the growth of lateral buds

auxin

hormone that inhibits lateral stem growth

branches do not block sunlight from other branches

benefits of apical dominance

1. siphonostele eustele
2. vascular cambium present
3. secondary growth present

pinus stele

1. periderm
2. cortex
3. resin duct
4. vascular cambium
5. phloem and xylem
6. annual rings
7. pith

secondary growth stele anatomy

bark

name for tissues outside of the vascular cambium

wood

name for tissues inside the vascular cambium

dimorphic shoots

pinus stem morphology

1. long shoot
2. spur shoot

two types of shoots present in a dimorphic shoot plant

long shoot

derives the spur shoots

spur shoots

derives most of the leaves

1. simple leaf
2. needle-like
3. evergreen
4. arise within fascicles

pinus leaf morphology characteristics

fascicle

leaf aggregate

evergreen

leaf that has function for more than one season

1. thick cuticle
2. epidermis
3. stomate
4. hypodermis
5. mesophyll
6. resin duct
7. vascular cylinder
8. endodermis
9. transfusion tissue
10. xylem and phloem

pinus leaf anatomy

adapted for xeric habitats

pinus leaf anatomy key characteristic

1. thick cuticle
2. sunken stomates
3. hypodermis
4. mesophyll
5. endodermis
6. transfusion tissue

structures in the pinus leaf that help it retain water

1. megagametophyte surrounds the embryo
2. cotyledons
3. apical meristem
4. hypocotyl
5. radicle
6. root apical meistem
7. suspensor

pinus embryo structure

cotyledons

embryo leaves

hypocotyl

embryo stem

radicle

embryo root

1. prothallial cells
2. generative cell
3. tube cell
4. winged exine

pollen grain structure

anemophilous pollination

term used to describe wind pollination

non-flagellated

pinus sperm

monoecious

micro- and megasporangia on the same plant

dioecious

micro- and megasporangia on different plants

monoecious

pinus sex habit

1. microsporophyll
2. 2 microsporangia per microsporophyll

microstrobilus structure

1. ovuliferous scale
2. bract
3. 2 ovules per ovuliferous scale

megastrobilus structure

ovuliferous scale

ovule bearing branches

microstrobili on lower branches, megastrobili on upper branches

pinus strobili position

ensures cross-pollination and genetic diversity

reason behind pinus strobili positon

1. integument
2. micropyle
3. pollen chamber
4. megasporangium
5. megagametophyte
6. megaspore wall
7. archegonium

pinus ovule anatomy

polyembryony

1+ embryo/seed made at a time

wind

pinus seed dispersal

generative cell

undergoes mitosis to produce a sterile cell and a spermatophyte

2 (2 oocytes)

number of archegonia produced by the megagametophyte

two zygotes

result of the two archegonia undergoing syngamy

embryo

result of a zygote undergoing mitosis

natural selection

occurs in a polyembryonic ovule so that there is only one embryo

anthophyta

magnoliophyta synonym

angiosperms and flowering plants

magnoliophyta common name

\~235,000 species

magnoliophyta worldwide diversity

\~3,500

magnoliophyta alabama diversity

most diverse tracheophyte phylum

magnoliophyta key characteristic

1. magnoliopsida
2. liliopsida

magnoliophyla classes

dicots and eudicots

magnoliopsida common names

\~170,000 species

magnoliopsida worldwide diversity

monocots

liliopsida common name

\~65,000 species

liliopsida worldwide diversity

2 cotyledons

magnoliopsida number of cotyledons