Is Ephedra a Gnetophyte?

Is Ephedra a Gnetophyte?

gnetophyte, any member of the division Gnetophyta, a small group of gymnospermous vascular plants that are represented by three living genera: Ephedra, Gnetum, and Welwitschia. There are 65 species in the genus Ephedra, 30 or more in Gnetum, but only one in Welwitschia.

What are the classification and economic importance of Ephedra?

1. Ephedrine, an alkaloid obtained from several species of Ephedra, is used in the preparation of medicines for treating asthama, bronchitis, cough, cold, nasal disorder and hay fever. In India, the ephedrine is obtained from Ephedra gerardiana, E.

What are Angiospermic characters of Gnetales?

Some of the resemblances between Gnetum and angiosperms are under mentioned:

• The general habit of the sporophyte of many species of Gnetum resembles with angiosperms.
• Reticulate venation in the leaves of Gnetum is an angiospermic character.
• Presence of vessels in xylem is again an angiospermic character.

What group of plants is Ephedra in?

gymnosperm shrubs
Ephedra, genus of 65 species of gymnosperm shrubs of the family Ephedraceae. Ephedra is an evolutionally isolated group and is the only genus in the order Ephedrales (division Gnetophyta).

Is Gnetophyta a Viridiplantae?

VIRIDIPLANTAE. Gnetophyta (ne-TA-fa-ta) is derived from the Moluccan Malay word Gamemu and plant (phyto -φυτο). The reference is to Gamemu (the Moluccan word for Gnetum). The gnetophytes are reduced to three far-flung and remarkably different genera (each genus in its own order).

Are Gnetophyta a paraphyletic group?

An interesting outcome of their molecular analyses is the monophyletic clade, Pinaceae + Gnetophyta (called the Gne-Pine Hypothesis, Figure 2-A). FIGURE 1. This is a paraphyletic group which includes the Mesozoic pteridosperms, cycads, conifers, ginkgophytes and the cycadeiods+gnetophytes+angiosperms..

What are angiosperm features of Ephedra plant?

Xylem consists of tracheids, vessels and xylem parenchyma. Due to the presence of the vessels the Ephedra resembles angiosperms. The phloem consists of sieve cells, phloem parenchyma and albuminous cells. Phloem and xylem are separated by a narrow strip of cambium.

How do I identify an Ephedra plant?

Ephedra is a most unusual and thus easily remembered shrub and it is very common in semi-desert sand, rock, mesas, and canyons. Leaves are reduced to tiny dark scales; the number of leaves (and bracts) grouped together is key in identifying the various species: E. torreyana has leaves and bracts grouped in threes; E.

What is order Gnetales?

Definitions of order Gnetales. chiefly tropical or xerophytic woody plants; practically unknown as fossils but considered close to the ancestral line of angiosperms. synonyms: Gnetales. type of: plant order.

What are the Angiospermic characters in ephedra?

Due to the presence of the vessels the Ephedra resembles angiosperms. The phloem consists of sieve cells, phloem parenchyma and albuminous cells. Phloem and xylem are separated by a narrow strip of cambium.

How many species of Ephedra are there?

There are 40 known ephedra species distributed among the arid and semiarid regions of Asia, Europe, northern Africa, western North America, and South America.

What characteristics do members of phylum Gnetophyta have in common with angiosperms?

Gnetophytes (approximately 70 extant species) They have several traits in common with angiosperms, such as vessel elements in the xylem, double fertilization, and a covering over their seeds (more on this in labs 21 and 22). Even their leaves are angiosperm-like, with netted venation.

What is the difference between Ephedra and Gnetales?

While Ephedra has an archegonium, the complex female gametophytes of both Gnetum and Welwitschia are devoid of archegonia. The members of Gnetales are specialized endpoints in evolu­tion which are not closely related to any present-day gymnosperms or angiosperms.

What are the different genera of Gnetales?

Formerly, these genera (Ephedra, Welwitschia and Gnetum) were considered to be the only living representatives of family Gnetaceae of order Gnetales. But Sporne (1965) and others divided Gnetales into three families, each having a single genus, viz. Gnetaceae (Gnetum), Welwitschiaceae (Welwitschia) and Ephedraceae (Ephedra).

How many species are there in the genus Ephedra?

Ephedra, the lone genus of family Ephedraceae of order Gnetales, is represented by some 40 species. It is distributed in mountainous or rocky places, or in sandy desert regions throughout the world. Most of the species are shrubs, and a few are lianes.

What is the difference between Ephedra Gnetum and Welwitschia?

Ephedra and Gnetum include trees, shrubs, vines and climbers with proliferate branching and decussate or whorled phyllotaxis. Welwitschia is unusual in having a very condensed, unbranched stem and two persistent leaves that grow for the entire life of the plant.