What is the Difference Between Cycas and Pinus

The main difference between Cycas and Pinus is that the Cycas is a plant genus consisting of small, palm-like trees whereas Pinus is a plant genus consisting of tall, branched trees. 

Cycas and Pinus are two genera of gymnosperms. Both of them develop naked seeds, which are not covered by a fruit. Furthermore, Cycas is a dioecious tree while Pinus is a monoecious tree.

Key Areas Covered

1. What is Cycas
     – Definition, Characteristics, Importance
2. What is Pinus
     – Definition, Characteristics, Importance
3. What are the Similarities Between Cycas and Pinus
     – Outline of Common Features
4. What is the Difference Between Cycas and Pinus
     – Comparison of Key Differences

Key Terms

Cycas, Male and Female Cones, Leaves, Pinus, Seed, Stem

What is Cycas

Cycus is a genus with short, palm-like trees commonly called cycads. It belongs to the division Cycadophyta. Cycads are believed to have evolved in Permian, 280 million years ago. So far, about 305 species of cycads have been identified all over the world. Among them, around 70% of the species are native to China, Vietnam, Australia, South Africa, and Mexico.

Figure 1: Cycus tici

The stem of cycads is covered with a corky bark. At the end of the stem, leaves occur as a crown. The leaves of cycads are large, hard, and elongated. The new leaves grow from the center of the crown in the form of a circinate-ptyxis. Some cycads shed their leaves in the dry season. The roots of cycads form a symbiotic relationship with nitrogen-fixing bacteria.

Figure 2: Cycas Male Cone

Cycads are dioecious plants that develop male and female reproductive structures in separate plants. The male reproductive structure is cone-shaped while the female reproductive structure is leafy. The seeds of the cycads are covered with red or yellow color flesh. The growth of cycads occur very slowly and they can survive up to 1000 years.

What is Pinus

Pinus is a genus with coniferous trees commonly called pines. It belongs to the division Pinophyta. Around 115 pine species have been identified worldwide. Most pines are native to the Northern hemisphere. Most pines can grow up to 147 feet. The diameter of their crown can be 30 feet. The bark of the pines is thick and scaly. The branches of the pines appear along with common, spiral points of the stem. Generally, pines are evergreen trees and their leaves are needle-like.

Figure 3: Pinus densiflora

Pines are monoecious plants which produce male and female cones within the same tree. Their pollination occurs through the wind. The seeds of the pine contain wings. Woodpeckers and squirrels eat the seeds of pine. The broken bark of pine secretes resins that are highly inflammable.

Figure 4: Pine Cones

Similarities Between Cycas and Pinus

• Cycas and Pinus are two genera of gymnosperms.
• They do not develop a fruit which covers the seed. Their seeds are endospermic and the endosperm is haploid.
• Both do not develop flowers. Their cones are unisexual.
• The main pollination method of them is the wind.
• Their sporophylls, the leaves, which bear sporangia occur in cones.
• Their leaves are mainly needle-like.
• They develop a strong stem and a long, tap root system.
• They have a well-developed vascular system. Their xylem is made up of tracheids; no companion cells in the phloem; the tracheids in the secondary xylem do not possess spiral thickenings.

Difference Between Cycas and Pinus

Definition

Cycas refers to a genus of several palm-like cycads Old World tropical plants while Pinus refers to a large genus of evergreen coniferous trees called pines, mostly found in the northern hemisphere. This constitutes the basic difference between Cycas and Pinus.

Height

One of the visually identifiable difference between Cycas and Pinus is their height. Cycads are short while pines are tall.

Stem

Also, the stem of cycads is thick, and cylindrical while the stem of pines is strong, cylindrical and scaly.

Annual Rings

Another difference between Cycas and Pinus is that the cycads do not develop annual rings, while the pines develop annual rings.

Branching

Cycad stem can be either branched or unbranched while the stem of pine is characterized by ex-current branching.

Leaves

Another clear difference between Cycas and Pinus is their leaves. Cycads have large, pinnate leaves, which are spirally-arranged while pines have either needle-like or scaly leaves.

Roots

Furthermore, the two types of roots in cycads are tap roots and coralloid while the two types of roots in pines are tap roots and mycorrhizal roots.

Monoecious or Dioecious

Moreover, the cycads are dioecious while pines are monoecious.

Male Cones

You can observe a difference between Cycas and Pinus in their cones too. The male cone of cycads is large and terminal, bearing numerous microsporophylls while male cone of pines is small and clustered.

Female Cone

The female cone of cycads is a whorl and loosely arranged while the female cone of pines is compact.

You can also observe many other differences in their reproductive organs.

Microspores

Microspores of cycads are not winged while the microspores of pines are winged.

Megasporophyll

Megasporophylls of cycads are large and each bear 1-5 big ovules while megasporophyll of pine bear 2 ovules.

Male Gametes

Male gametes are large and multiflagellated in cycads while male gametes are small and non-motile in pines.

Embryos

Cycads develop a single embryo while pines develop four embryos but, one becomes functional.

Seeds

Cycad seeds have no perisperm, but they have two cotyledons, testa fleshy and colored while pine seeds have a perisperm; numerous cotyledons; testa dry. Furthermore, cycads seeds have no wings while pine seeds have wings. We can say this also as an imporatnt difference between Cycas and Pinus.

Germination

Also, cycads show hypogeal germination while pines show epigeal germination.

Conclusion

Cycas is a genus of short trees, which are palm-like. Pinus is another genus with coniferous trees. Cycads have a leafy crown on top of the stem. They are dioecious plants. Pines produce branches and their leaves are needle-like. They are monoecious plants. The main difference between Cycas and Pinus is the characteristics of trees.

Reference:

1. Taylor, Amie. “Characteristics of the Cycads.” Home Guides | SF Gate, 7 Oct. 2016, Available Here
2. Espoz, Justine Bayod. “Characteristics of Pine Trees.” Hunker.com, Hunker, 22 July 2010, Available Here

Image Courtesy:

1. “Cycus tici” By Rahat (Talk * Contributions) – Own work (CC BY-SA 4.0) via Commons Wikimedia   
2. “Cycas male cone” By L. Shyamal – Own work (CC BY-SA 3.0) via Commons Wikimedia    
3. “Pinus densiflora Kumgangsan” By yeowatzup at Flickr – Flickr (CC BY 2.0) via Commons Wikimedia 
4. “Pine-Pine-Cones-Pine-Needles-Tree-323557” (CC0) via Max Pixel

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