* The Oriental plane (Platanus orientalis) is a native of Asia. It rises with a straight, smooth, branching stem to a great height, with palmated leaves, and long pendulous peduncles, sustaining several heads of small close-sitting flowers. The seeds are downy, and collected into round, rough, hard balls. The Occidental plane (Platanus occidentalis), which grows to a great height, is a native of North America, where it is popularly called sycamore, buttonwood, and buttonball, names also applied to the California species (Platanus racemosa).

* In science, this word (instead of plain) is almost exclusively used to designate a flat or level surface.

Plane angle, the angle included between two straight lines in a plane. -- Plane chart, Plane curve. See under Chart and Curve. -- Plane figure, a figure all points of which lie in the same plane. If bounded by straight lines it is a rectilinear plane figure, if by curved lines it is a curvilinear plane figure. -- Plane geometry, that part of geometry which treats of the relations and properties of plane figures. -- Plane problem, a problem which can be solved geometrically by the aid of the right line and circle only. -- Plane sailing (Naut.), the method of computing a ship's place and course on the supposition that the earth's surface is a plane. -- Plane scale (Naut.), a scale for the use of navigators, on which are graduated chords, sines, tangents, secants, rhumbs, geographical miles, etc. -- Plane surveying, surveying in which the curvature of the earth is disregarded; ordinary field and topographical surveying of tracts of moderate extent. -- Plane table, an instrument used for plotting the lines of a survey on paper in the field. -- Plane trigonometry, the branch of trigonometry in which its principles are applied to plane triangles.

Objective plane (Surv.), the horizontal plane upon which the object which is to be delineated, or whose place is to be determined, is supposed to stand. -- Perspective plane. See Perspective. -- Plane at infinity (Geom.), a plane in which points infinitely distant are conceived as situated. -- Plane iron, the cutting chisel of a joiner's plane. -- Plane of polarization. (Opt.) See Polarization. -- Plane of projection. (a) The plane on which the projection is made, corresponding to the perspective plane in perspective; -- called also principal plane. (b) (Descriptive Geom.) One of the planes to which points are referred for the purpose of determining their relative position in space. -- Plane of refraction or reflection (Opt.), the plane in which lie both the incident ray and the refracted or reflected ray.

He planed away the names . . . written on his tables. Chaucer.

What student came but that you planed her path. Tennyson.