| 词条 | Ephedra aspera |
| 释义 |
| image = Ephedra-aspera-20080322.JPG | image_caption = | genus = Ephedra | species = aspera | authority = Engelm. ex S.Wats. | synonyms_ref = [1] | synonyms =
}}Ephedra aspera is a species of Ephedra known by the common names rough jointfir, boundary ephedra, and pitamoreal. It is native to the southwestern United States from California to Texas and parts of northern Mexico as far south as Zacatecas.[1][2] It is a resident of varied woodland and scrub plant communities.[3] DescriptionEphedra aspera is a highly branched shrub often exceeding {{convert|1|m|ft}} in height made up of many long yellow-gold twigs. Its small leaves are just a few millimeters long. Male plants bear pollen cones 4 to 7 millimeters long. Female plants may be darker to reddish in color, bearing seed cones which are slightly larger than those of the male plant and contain only one seed each.[4]Shrubs are 0.5--1.5 m in length. Bark is gray, cracked and fissured. Branches are opposite or whorled, rigid, angle of divergence is about 30°. Twigs are pale to dark green, becoming yellow with age, not viscid, slightly to strongly scabrous, with numerous longitudinal grooves; internodes are 1--6 cm in length. Terminal buds conic, 1--2 mm, apex obtuse. Leaves opposite (rarely in whorls of 3), 1--3(--5) mm, connate to 1/2--7/8 their length; bases thickened, brown, shredding with age, ± persistent; apex obtuse. Pollen cones 2 (rarely 1 or whorled) at node, obovoid, 4--7 mm, sessile or rarely on short peduncles; bracts opposite, 6--10 pairs, yellow to red-brown, obovate, 3--4 × 2--3 mm, membranous; bracteoles slightly exceeding bracts; sporangiophores 4--5 mm, 1/2 exserted, with 4--6 sessile to short-stalked (less than 1 mm) microsporangia. Seed cones usually 2 at node, ovoid, 6--10 mm, sessile or on short, scaly peduncles; bracts opposite, 5--7 pairs, circular, 4--7 × 2--4 mm, membranous, with red-brown thickened center and base, margins entire. Seed 1, ellipsoid, 5--8 × 2--4 mm, light brown to brown, smooth to slightly scabrous. References1. ^1 Kew World Checklist of Selected Plant Families 2. ^Biota of North America Program, 2013 county distribution map 3. ^Jepson Manual Treatment: Ephedra aspera 4. ^Flora of North America External links{{Commons category-inline|Ephedra aspera}}
8 : Ephedraceae|North American desert flora|Flora of Mexico|Flora of the Southwestern United States|Flora of the California desert regions|Flora of the Chihuahuan Desert|Flora of the Sonoran Deserts|Natural history of the Mojave Desert |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。