The conifers have the Most massive = Giant

The conifers have the Most massive = Giant Sequoias Sequoiadendron giganteum (Cupressaceae) ...

..The Tallest = Coastal Redwood (Sequoia sempervirens) (Cupressaceae) .

.. And the oldest = Bristlecone Pine Pinus longaeva (Pinaceae). Welwitschia mirabilis Welwitschiaceae

young plant Note 2 strap-like leaves http://waynesword.palomar.edu/images/welwit3b.gif

As Welwitschia grows the 2 leaves split into many sections. http://www.biosci.ohio-state.edu/~plantbio/images/greenhouseimages/welwitschia2.jpg Welwitschia is dioecious with separate male and female

plants. Plant with female cones Plant with male

cones Welwitschia mirabilis can live for up to 2000 years by which time the two leaves have shredded into multiple straps. ttp://www.cactusandsucculent.org/riviste/2000/fascicolo-4/foto/welwitschia-mirabilis.jpg

Courtesy of Amy Dieckmann 05 Escalante National Monument, Ephedra in the foreground Plant Male strobili (cones)

Ephedra Female strobilus (cone) From Tree of Life Web Site, U. of AZ Gnetum, a woody plant with vessels

Gnetophytes and Angiosperms have vessels. a. Longitudinal tracheid of pine. b. Vessel of a

hardwood (early wood) c. Vessel of a hardwood (late wood)

c. Hardwood fiber cell (provides support) e. Trachied of

a hardwood. Anthophyte Hypothesis Gnetifer

Hypothesis Two trees illustrating the Anthophyte vs Gnetifer Hypotheses Anthophytes (Extinct)

(Extinct) Gnetifers