The tree ferns are the ferns that grow with a trunk elevating the fronds above ground level.
 Most tree ferns are members of the "core tree ferns", belonging to the families Dicksoniaceae, Metaxyaceae, and Cibotiaceae in the order Cyatheales.
 In addition to those families, many ferns in other groups may be considered tree ferns, such as several ferns in the family Osmundaceae, which can achieve short trunks under a metre tall, and particularly ferns in the genus "Cibotium", which can grow ten metres tall.
 Fern species with short trunks in the genera "Blechnum, Calochleana, Cnemedaria, Culcita" (Europe's only tree fern), "Cystodium, Leptopteris, Lophosoria, Sadleria, Thyrsopteris" and "Todea" could also be considered tree ferns in a liberal interpretation of the term.
Gymnocarpium is a small genus of ferns, called oak ferns.
 It was once placed with various other groups, including the dryopteroid ferns and the athyrioid ferns.
 Cladistic analysis has demonstrated that "Gymnocarpium" and "Cystopteris" form a natural but relatively primitive clade that is basal to the asplenoid, thelypterioid, and athyrioid ferns comprehensively.
Cobaea is a genus of flowering plants including about 20 species of rapid growing, ornamental climbers native to Mexico.
 The botanical name honors Father Bernabé Cobo, Spanish Jesuit of the seventeenth century, naturalist, and resident of America for many years.
 The woody stems can reach 20 ft .
 Leaves are alternate lobed with opposite pairs and tendrils.
 In late summer to early spring, the large, bell-shaped flowers are borne profusely and singly along the stems with bright green, violet, or purple in colors.
 The plants can become invasive in some areas, and are common weeds in New Zealand.
Lophosoria quadripinnata is a species of fern that, according to DNA molecular analysis, belongs to the Dicksoniaceae family, where it is placed in the genus "Lophosoria".
 It is found in the Americas spanning from Cuba and Mexico to Chile.
 In Chile it is present in the area between Talca and Aysén including Juan Fernández Islands.
 In Argentina it grows only in the humid valleys of western Neuquén and Río Negro Province.
 Diamondleaf fern is a common name.
 In Spanish it is known as 'ampe' (from the Mapudungun añpe) or palmilla, but one has to remember that there are several species of ferns called "palmillas" that have larger or smaller fronds, and which grow in colder climates.
 It is a medium-sized plant, growing to about 4–5 feet (though 10–12 feet in a sheltered place at Arduaine Garden in Argyll, Scotland) and even though the rhizome does not grow a trunk, it is clearly related to the other tree ferns due to features that were apparently already present in their common ancestor, like 'pneumathodes', and the rhizome which changed from the dorsiventral symmetry typical of the other ferns, to a radial symmetry typical of tree ferns.
 Their large and multiple pinnate fronds, with the petiole raised adaxially, and the hairs on the rhizome and lower part of the petioles, also resemble those of tree ferns.
 To identify the species, use the position and characteristics of the spores found on the fertile fronds.
 The genus already existed in the Cretaceous Period in southern Gondwana according to fossil remains found in Antarctica.
 The species is well known as an ornamental plant.
Thelypteris (maiden ferns) is a genus of ferns in the family Thelypteridaceae, order Polypodiales.
 If the genus is defined fairly broadly, it contains 875 species, many of which are extremely similar to one another, and is found nearly worldwide.
 The ferns are terrestrial, with the exception of a few which are lithophytes (grow on rocks).
 The bulk of the species are tropical, although there are a number of temperate species.
Frond dimorphism refers to a difference in ferns between the fertile and sterile fronds.
 Since ferns, unlike flowering plants, bear spores on the leaf blade itself, this may affect the form of the frond itself.
 In some species of ferns, there is virtually no difference between the fertile and sterile fronds, such as in the genus "Dryopteris", other than the mere presence of the sori, or fruit-dots, on the back of the fronds.
 Some other species, such as "Polystichum acrostichoides" (Christmas fern), or some ferns of the genus "Osmunda", feature dimorphism on a portion of the frond only.
 Others, such as some species of "Blechnum" and "Woodwardia", have fertile fronds that are markedly taller than the sterile.
 Still others, such as "Osmunda cinnamomea" (Cinnamon fern), or plants of the family Onocleaceae, have fertile fronds that are completely different from the sterile.
Thelypteris kunthii, the Kunth's maiden fern or southern shield fern, is the most common of the maiden ferns in the southeastern United States south of the fall line.
 It ranges westward to eastern Texas.
 It usually grows in moist to dry terrestrial situations, but can also be epipetric.
 It often grows as a greenhouse escape in areas north of its usual range.
Cryptogramma is a genus of ferns known commonly as rockbrakes or parsley ferns.
 They are one of the three genera in the Cryptogrammoideae subfamily of the Pteridaceae.
 "Cryptogramma" ferns can be found in temperate regions on several continents worldwide.
 These ferns have two kinds of leaves which often look so different that at first glance they appear to belong to different plants.
 The fertile leaves have long, narrow, bumpy segments with undersides covered thickly in sporangia.
 The edges of the segments may curl back to cover the sporangia, forming a false indusium.
 The sterile leaves have thinner, wider segments which may be rounded and resemble the leaves of parsley.
 These ferns grow in rocky areas, often in crevices and cracks.
Phegopteris is a genus of ferns known collectively as the beech ferns.
 Traditionally this genus included only the first three species listed.
 However, recent genetic evidence clearly shows that the genera "Macrothelypteris" and "Pseudophegopteris", as well as other segregates from the genus "Thelypteris", are closely related to "Phegopteris" in a single clade, and so are now included as "Phegopteris" species.
Argyrochosma is a genus of ferns known commonly as false cloak ferns.
 The genus is included in the Cheilanthoideae subfamily of the Pteridaceae.
 Species now in this genus were previously treated as members of related genera "Notholaena" or "Pellaea" but were segregated into their own genus in 1987.
 These ferns, of which there are about 20 species, are mostly native to the Americas, from North to South and including the Caribbean, while one species, "A. connectens", is known from Sichuan, China.
 They are commonly found growing in cracks between rocks.
 Their leaves are generally shorter than 40 centimeters and have rounded bluish or grayish green segments.
 Often the lower surface of the segments is coated in a white dust, and the sporangia contain brown spores.

Question: While the Thelypteris is a genus of ferns, what is the genus of Cobaea?
Answer: genus of flowering plants