Question: Are Cycad and Peperomia both seed plants?

Context articles: Runcaria
Cycad
Dioon edule
Peperomia
Lagenostoma
Secondary growth
Cryptogam
Pollination
Diaspore (botany)
Serotiny

Runcaria heinzelinii is an extinct species of plant from the Middle Devonian of Belgium.
 It is the only species classified under the genus Runcaria.
 It was a precursor to seed plants, predating the earliest of the latter by about 20 million years.
 The fossil pieces of "Runcaria heinzelinii" that have been found are short branched stems that at their tips have a radially symmetrical megasporangium surrounded by a cupule.
 The megasporangium has a multilobed integument, and there is an extension on the megasporangium that suggests an adaptation to wind pollination.
 Thus, this fossil plant has all of the qualities of seed plants except for a solid seed coat and a system to guide the pollen to the ovulum.
 It sheds new light on how the seed may have evolved.
Cycads are seed plants with a long fossil history that were formerly more abundant and more diverse than they are today.
 They typically have a stout and woody (ligneous) trunk with a crown of large, hard and stiff, evergreen leaves.
 They usually have pinnate leaves.
 The individual plants are either all male or all female (dioecious).
 Cycads vary in size from having trunks only a few centimeters to several meters tall.
 They typically grow very slowly and live very long, with some specimens known to be as much as 1,000 years old.
 Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group.
Dioon edule, the chestnut dioon, is a cycad native to Mexico, also known as palma de la virgen.
 Cycads are among the oldest seed plants and even pre-date the dinosaurs.
 It belongs to the Zamiaceae plant family within the order Cycadales.
 The genus name "Dioon" means "two-egged", referring to the two ovules (see photo below).
Peperomia (radiator plant) is one of the 2 large genera of the Piperaceae family, with more than 1000 recorded species.
 Most of them are compact, small perennial epiphytes growing on rotten wood.
 More than 1500 species have been recorded, occurring in all tropical and subtropical regions of the world, though concentrated in Central America and northern South America.
 A limited number of species (around 17) are found in Africa.
Lagenostoma is a genus of seed ferns (Pteridospermophyta), based on ovules preserved in coal balls from the Six Inch Coal of the Hough Hill Colliery near Stalybridge, England.
 Distinctive stalked glands enabled Oliver and Scott to attribute these seeds to fernlike foliage of "Sphenopteris hoeningshauseni" in the same coal balls.
 This was the first recognition that some Carboniferous fernlike leaves had seeds, and so were not pteridophytes, but rather Pteridospermophyta, or seed ferns.
 The realization that seed plants as well as spore plants had fernlike leaves was a major contribution to the evolutionary history of plants.
In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate, and gives rise to primary tissue.
 Secondary growth occurs in most seed plants, but monocots usually lack secondary growth.
 If they do have secondary growth, it differs from the typical pattern of other seed plants.
A cryptogam (scientific name Cryptogamae) is a plant (in the wide sense of the word) that reproduces by spores, without flowers or seeds.
 "Cryptogamae" (Greek κρυπτός "kryptos ", "hidden" + γαμέω , "gameein ", "to marry") means hidden reproduction, referring to the fact that no seed is produced, thus cryptogams represent the non-seed bearing plants.
 Other names, such as "thallophytes", "lower plants", and "spore plants" are also occasionally used.
 As a group, Cryptogamae are the opposite of the Phanerogamae (Greek φανερός , "phaneros " = "visible") or Spermatophyta (Greek σπέρμα , "sperma " = "seed" and φυτόν , "phyton " = "plant"), the seed plants.
 The best known groups of cryptogams are algae, lichens, mosses and ferns, but it also includes non-photosynthetic organisms traditionally classified as plants, such as fungi, slime molds, and bacteria.
Pollination is the process by which pollen is transferred to the female reproductive organs of a plant, thereby enabling fertilization to take place.
 Like all living organisms, seed plants have a single major purpose: to pass their genetic information on to the next generation.
 The reproductive unit is the seed, and pollination is an essential step in the production of seeds in all spermatophytes (seed plants).
In botany, a diaspore is a plant dispersal unit consisting of a seed or spore "plus" any additional tissues that assist dispersal.
 In some seed plants, the diaspore is a seed and fruit together, or a seed and elaiosome.
 In a few seed plants, the diaspore is most or all of the plant, and is known as a tumbleweed.
Serotiny is an ecological adaptation exhibited by some seed plants, in which seed release occurs in response to an environmental trigger, rather than spontaneously at seed maturation.
 The most common and best studied trigger is fire.
 However, the term "serotiny" refers more broadly to plants that release their seeds over a long period of time, irrespective of the trigger or whether release is spontaneous.
 In this sense, the term is synonymous with bradyspory.