What is so tricky about a citrus pip?

By Chelsie Vandaveer

February 20, 2003

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Killer Picks: Meyer Lemon, Navel Orange, Key Lime, Venous Orange—>Click here.

Seeds from flowering plants are generally considered simple things to most people. Stuck into the soil, the seed grows into a plant. It is generally known that what a plant becomes is determined by its genes—half come from the mother plant which produced the seed and half from the father which donated the pollen. But seeds are not simple.

Citrus Fruits, Orange, Grapefruit, Lemon, Sliced in Half Showing Different Colours, Europe

Citrus seeds or pips do not necessarily need the egg and sperm. Limes, grapefruit, mandarins, oranges, and lemons may form multiple embryos (polyembryony). Citrus Fruits, Orange, Grapefruit, Lemon, Sliced in Half Showing Different Colours, Europe Photographic Print Reinhard Buy Photographic Print at AllPosters.com

The ovule and its outer layers becomes the seed. The outer layers are the nucellus, nutritive tissue for the future embryo, and the integument, a protective layer which will become the seed coat. Both of these layers are diploid (two sets of chromosomes) tissue supplied by the mother plant.

The inner portion of the ovule contains a central cell with two nuclei, three antipodal cells, two synergid cells and an egg cell. The nucleus of each of these cells is haploid (single set of chromosomes).

The pollen grain contains three haploid cells—two sperm cells and a tube cell. The tube cell's purpose is to transport the two sperm cells to the ovule. One of the synergids takes the sperm cells and directs one to the egg cell and one to the central cell.

The egg cell fuses with one sperm cell to become a zygote. The zygote begins dividing and becomes the embryo or baby plant inside the seed. The second sperm cell fuses with the two nuclei of central cell to become endosperm, more nutritive tissue for the embryo. The antipodals and synergids are lost. When the seed germinates, it splits opens and the embryo grows into a plant—one seed, one plant.

Citrus seeds or pips do not necessarily need the egg and sperm. Limes, grapefruit, mandarins, oranges, and lemons may form multiple embryos (polyembryony). Clones of the mother plant, these embryos develop from the nucellus layer of the seed. Several plants, called adventitious apomicts, can grow from a single seed.

Home Citrus Growers in the U.K. has numerous great photographs of different citrus plants and their fruit, proving that citrus make good potted plants. To view the photographs, click on the link:

http://www.homecitrusgrowers.co.uk/citrusvarieties/commoncitrus1.html

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Improved Meyer Lemon
Dwarf Citrus Tree

Springhill Nursery®

A taste of the tropics! Dwarf citrus trees bear fragrant flowers followed by tasty fruit! The Improved Meyer Lemon has fruits year-around.

(Move plants indoors for winter in Northern zones.) Kits includes one plant, 10'' pot with saucer and soil. Shipped in 4'' pot.

Citrus lemon 'Improved Meyer'

Hardiness Zone: 9-10 (24° F)

Improved Meyer Lemon Dwarf Citrus Tree Ships In The Spring Click here - Save $20 on $50 order

Unique Characteristics: Fruit is coveted by California chefs for its haunting sweetness. Used to flavor everything from fresh fish to lemon sherbet. Hardier than most lemons, extremely adaptable as a container plant and to northern house conditions. Will flower and bear fruit year round. Can be kept as small as 24 inches in a container. Bears fruit in 1-3 years.

Additional Information: In Northern climates, plants should be grown outdoors during temperate months, then moved inside at the onset of freezing weather. This will encourage more fruit production.

What is the Meyer lemon? Weird Plants - February 6, 2003

Navel Orange Dwarf Citrus Tree

Springhill Nursery®

Produces seedless, three inch fruit mid-fall to mid-spring, fragrant white flowers in summer. Evergreen foliage.

Kit includes one plant, 10'' planter, saucer and soil.

Shipped in 4'' pot.

Citrus sinensis 'Washington Navel'

Hardiness Zone: 9-10 (24° F)

Navel Orange Tree Kit Ships In The Spring Click here - Save $20 on $50 order

Unique Characteristics: Valued for its fresh use; ease of peeling. Adaptability as a container plant. Will flower and bear fruit year round. Bears fruit in 1-3 years.

Additional Information: In Northern climates, plants should be grown outdoors during temperate months, then moved inside at the onset of freezing weather. This will encourage more fruit production.

What is a navel orange? Weird Plants - February 13, 2003

Dwarf Key Lime Fruit Trees

Gurney's Seed and Nursery®

Fun, Flowers and Fragrance, Too!

Glossy evergreen foliage, sweetly scented flowers and edible fruit in one! The Dwarf Key Lime can be moved outdoors in summer, so the bees take care of pollination for you.

Varieties grow from 2-5 feet tall. Pick citrus in 1-3 years, figs and pomegranates in 2-4 years and bananas in 3-5 years.

Potted plants.

Hardiness Zone: 9-10 (30° F)

Dwarf Key Lime Fruit Trees Ships In Both Spring And Fall Click here - $20 off any order for $50 or more at Gurneys.com!

Comments: Four hours or more of direct sunlight from a south window. Let plant approach dryness before watering. Average indoor humidity levels. Day temperature 65-70 degrees F; night temperature 50-55 degrees F. Use an acid-balanced fertilizer throughout the year and add trace elements in spring. Leaves will drop if soil is too wet or too dry. High pH or high soluble salts can cause leaf yellowing. Will not bloom if light is too low. May need to hand pollinate for better fruit production.

How did arsenic poisoning lead to Key limes? Plants that Changed History - February 18, 2003

Dwarf Venous Orange Fruit Trees

Gurney's Seed and Nursery®

Fun, Flowers and Fragrance, Too!

The Dwarf Venous Orange offer evergreen foliage, sweetly scented flowers and edible fruit all in one!

Can be moved outdoors in summer, so the bees take care of pollination for you. Varieties grow from 2-5 feet tall. Pick citrus in 1-3 years.

Potted plants.

Hardiness Zone: 9-10 (30° F)

Dwarf Venous Orange Fruit Trees Ships In Both Spring And Fall Click here - $20 off any order for $50 or more at Gurneys.com!

Comments: Four hours or more of direct sunnlight from a south window. Let plant approach dryness before watering. Average indoor humidity levels. Day temperature 65-70 degrees F; night temperature 50-55 degrees F. Use an acid-balanced fertilizer throughout the year and add trace elements in the spring. Leaves will drop if soil is too wet or too dry. High pH or high soluble salts can cause leaf yellowing. Will not bloom if light is too low. May need to hand pollinate for better fruit production.

What is the most common fruit tree? Plants that Changed History - February 11, 2003