<Li> When the plant is mature, it produces cones and the cycle continues . </Li> <P> Conifer reproduction is synchronous with seasonal changes in temperate zones . Reproductive development slows to a halt during each winter season, and then resumes each spring . The male strobilus development is completed in a single year . Conifers are classified by three reproductive cycles, namely; 1 -, 2 -, or 3 - . The cycles refers to the completion of female strobilus development from initiation to seed maturation . All three types or reproductive cycles have a long gap in between pollination and fertilization . </P> <P> One year reproductive cycle: The genera includes Abies, Picea, Cedrus, Pseudotsuga, Tsuga, Keteleeria (Pinaceae) and Cupressus, Thuja, Cryptomeria, Cunninghamia and Sequoia (Cupressaceae). Female strobili are initiated in late summer or fall in a year, then they overwinter . Female strobili emerge followed by pollination in the following spring . Fertilization takes place in summer of the following year, only 3--4 months after pollination . Cones mature and seeds are then shed by the end of that same year . Pollination and fertilization occurs in a single growing season . </P> <P> Two - year reproductive cycle: The genera includes Widdringtonia, Sequoiadendron (Cupressaceae) and most species of Pinus . Female strobilus initials are formed in late summer or fall then overwinter . It emerges and receives pollen in the first year spring and become conelets . The conelet goes through another winter rest and in the spring of the 2nd year . The Archegonia form in the conelet and fertilization of the archegonia occurs by early summer of the 2nd year, so the pollination - fertilization interval exceeds a year . After fertilization, the conelet is considered an immature cone . Maturation occurs by autumn of the 2nd year, at which time seeds are shed . In summary, the 1 - year and the 2 - year cycles differ mainly in the duration of the pollination - fertilization interval . </P>

Name the phylum to which pines and firs belong