Plantae

• Plantae (Bryophytes, Pteridophytes, Gymnosperms)

  
• Evolution of land plants

  Plant adaptations to life on land include the development of many structures:

  • A water repellent cuticle
  • Stomata to regulate water evaporation
  • Specialized cells to provide rigid support against gravity
  • Specialized structures to collect sunlight
  • Alternation of haploid and diploid generations
  • Sexual Organs
  • Dispersal Mechanisms

  
• Bryophytes


  Spore-bearing, non-vascular plants, derived from Greek "Bryon" (mosses) and "Phyca" (plant), oldest plants on Earth (400 million years or more), lack true vascular tissues, lack leaves (have leaf-like scales), lack true roots (have root-like rhizoids), lack true stem, ground-hugging, no lignified tissues, prefer moist and humid environment, autotrophic and saprophytic

  
• Divisions of Bryophytes


  • Hepatophyta (Liverworts)
  • Anthocerophyta (Hornworts)
  • Bryophyta (Mosses)

  
• Bryophyta (Mosses)


  Body is usually leafy-like, prefer damp, shaded locations in temperate zones, dioecious, usually 1-10 cm tall, female mosses produce sporangia born on stalks on the tip of the thallus

  
• Hepaticophyta (Liverworts)


  Small, 2-20 mm wide, less than 100 mm, common forms: prostrate, flattened, ribbon-like or branching structure (thallus) - thallus liverworts, flattened "stem" with overlapping scales or leaves in three ranks - leafy liverworts
• Anthocerophyta (Hornworts)


  Grow as a thin rosette or ribbon-like gametophyte thallus, unique feature - erect, photosynthetic, horn-like sporophytes arising from thallus, some can live with association of Nostoc

  
• Common Hornwort Genera


  • Anthoceros
  • Phaeoceros

  
• Pteridophytes: Lycophytes & Ferns


  Spore-bearing, vascular, non-flowering plants, megaphyllous (lamina traversed by many veins and usually large), curling of young frond forming fiddle heads or croziers or circinate vernation, sporangia born on sori (sorus) usually found in the lower part of the leaves

  
• Lycopodiophyta (Lycophytes)


  Lycophylls (microphylls) are unbranched, sporangia develop laterally (relative to the stem) in the axils of specialized leaves termed sporophylls, aggregate of sporophylls with associated sporangia is known as a strobilus or cone

  
• Common Lycophyte Genera


  • Lycopodium
  • Huperzia
  • Lycopodiella

  
• Selaginellaceae


  Spirally arranged vegetative leaves that are isomorphic, single genus: Selaginella (Spike Moss), heterosporous, endosporic, ligule in the leaf

  
• Isoetaceae


  With a small corm-like stem that has roots attached below and leaves above, Isoetes (Quillworts)
• Monilophytes


  Spore-bearing, vascular, non-flowering plants, megaphyllous (lamina traversed by many veins and usually large), curling of young frond forming fiddle heads or croziers or circinate vernation, sporangia born on sori (sorus) usually found in the lower part of the leaves

  
• Major Monilophyte Lineages


  • Equisetales
  • Maratiales
  • Polypodiales
  • Ophioglossales
  • Psilotales
• Ophioglossales


  Fronds consist of a sterile segment (photosynthetic blade or lamina) and a fertile segment, underground rhizome gives rise to unbranched roots that lack root hairs, Botrychium (grape fern or moon wort), Ophioglossum (adder's tongue fern)

  
• Ophioglossales Genera


  • Botrychium
  • Ophioglossum

  
• Psilotales


  Lack true roots (only absorptive rhizoids arise from the rhizome), leaves are very reduced and peglike and may lack a vascular strand, fused synangium with forked appendage
• Psilotales Genera


  • Psilotum
  • Tmesipteris
• Equisetales


  Ribbed stems, reduced, whorled leaves that are usually marginally fused, sporangiophores, photosynthetic spores with elaters

  
• Equisetales Genus


  • Equisetum
• Marattiales


  Sporangia are fused into a common structure, a synangium, distinctive apomorphy is the occurrence of a polycyclic siphonostele
• Marattiales Genus


  • Angiopteris
• Polypodiales


  Leptosporangiate ferns, horizontal stem-rhizome, leaf=frond, petiole=stipe, ultimate leaflets or blade divisions are called pinnules

  
• Polypodiales Genera


  • Adiantum
  • Pteridium
  • Asplenium
  • Nephrolepis
• Origin of megaphylls (euphylls): three distinct types of homoplasic (analogous) structures called leaves occur in plants - (1) leaves on gametophytes of non vascular plants, (2) enations/microphylls of zosterophyllophytes and lycophytes, and (3) megaphylls; megaphylly evolution is summarized by the telom theory

  
• Synamorphies of megaphyllous plants: (1) their roots have exarch xylem, (2) they have megaphylls, and (3) they have a 30 kilobase inversion in the large single-copy region of their plastid DNA

  
• Fern sporophyte consists of a single axis, either a vertical shoot or a horizontal rhizome, that bears both true roots and megaphyllous leaves; the vascular system of the stem is an endarch siphonostele, a derived trait also present in equisetophytes and seed plants; at each node, a leaf trace diverges from the siphonostele, leaving a small segment of the vascular cylinder as just parenchyma (leaf gap); a vascular cambium has been reported to occur in one fern, Botrychium

  
• Seed Plants: Spermatophytes


  Wood, seeds, gymnosperms, angiosperms

  
• Cycadophyta


  Dioecious, habit, reproduction
• Cycadophyta Genus


  • Cycas
• Cycas riuminiana can be readily distinguished by the sterile part of the megasporophyll being broader than long

  
• Cycas silvestris


  Widespread forest species, current conservation status is Data Deficient
• Cycas riuminiana


  • Sterile part of the megasporophyll being broader than long

  
• Cycas silvestris


  • Megasporophylls having teeth which are almost of the same length
• Cycas silvestris is a widespread forest species. Its current conservation status can not be ascertained for lack of available field data. Its category is Data Deficient.
• Cycas riuminiana has at least 5 locations, continuing decline in quality of habitat, small population size: < 10 000 individuals (as per actual count of 20–25 individuals per 400 km2). Its category in the Philippines is Endangered.
• Cycads in the Philippines

  • Cycas aenigma
  • Cycas curanii
  • Cycas edentata
  • Cycas lacrimans
  • Cycas nitida
  • Cycas riuminiana
  • Cycas saxitilis
  • Cycas wadei
  • Cycas vespertilio
  • Cycas zambalensis
• Cardboard Cycad (Zamia furfuracea) is a Ginkgophyta
• Ginkgo biloba is a "relict species"