- Leaf Arrangement
- Alternate - Leaves attached one only at a point on a stem. Leaf attachments alternate from one side to the other down the stem. This option brings up leaves that are sessile or petiolate but not sheathed.
- Basal - Leaves attached mostly at or near the base of a plant. They will probably actually be alternate but will be too close together to tell.
- Clustered - A large undefined mass of leaves attached all around an area of the stem above the base. Refers here to Palms, yuccas and certain yucca-like plants. Most leaf arrangements that appear to be clustered may actually be alternate but they are so close together that this is difficult or impossible to tell so for description purposes they are considered "clustered".
- Fascicled - Several leaves appearing to be attached at a point on the stem. This is usually a winter condition where leaves are actually alternate but are so closely spaced on "short-shoots" that this cannot be seen. In summer, on "long shoots" leaves will usually be alternate. Searching here for either "alternate" or "fascicled" will bring up the same list of species.
- Imbricate - Very close overlapping of tiny leaves. Mostly junipers and tamarisks (salt-cedar).
- Moss like - Short stems thickly covered with very tiny leaves. True mosses and club-mosses (Selaginella).
- Opposite - Two leaves attached opposite each other at the same point on the stem.
- Rosette - Basal leaves arranged mostly symmetrically around the stem.
- sheathing - Leaves attached to the stem by a sheath. These plants are typically grasses, sedges, rushes and lily-type species. Sheathed leaves are usually alternate, but doing a search for "sheathing" will bring up only alternate leaves that are sheathed and not all the other alternate leaved plants.
- Whorled - Multiple leaves arranged in a ring around the stem. True whorling isn't common, but a search here for "whorled" will bring up apparent (not true) "whorled" also.
- Leaf Shape
- Cordate - Heart-shaped leaves with a deep sinus (indentation) where the petiole comes in to meet the base of the blade. Cordate leaves are also ovate or orbicular. Searches for cordate leaves will also bring up some, but not all, species that are described as ovate or orbicular.
- Cuneate - Wedge-shaped. The tip of the blade is much wider than the base and relatively flat rather than round. Choosing "cuneate" will also bring up species described as "spatulate" and sometimes "obovate".
- Filiform (filamentous) - Extremely narrow. Threadlike.
- Grasslike - Leaves of grasses and grasslike plants. Long, narrow and sheathed.
- Hastate - Triangular shaped with large prominent angular lobes extending out from each side of the base of the blade.
- Lanceolate - Blades much longer than wide. Widest at the base and tapering gradually to the pointed tip. Refers to the blades of simple leaves and leaflets of compound leaves.
- Linear - Narrow but not threadlike. Blade and petiole not distinguishable. Choosing "linear" will also bring up all species described as "grasslike", but choosing "grasslike" will not bring up all "linear" species.
- Moss-like - Very tiny blades without petioles. Leaves of True mosses and club mosses.
- Oblanceolate - Reversed lanceolate. Blades narrow at the base widening gradually to the wider tip. Blades much longer than wide.
- Oblong - Blade shaped like a rectangle with rounded ends. The two sides are relatively straight and parallel. Refers to the blades of simple leaves and the individual leaflets of compound leaves. This is a common shape of leaflets in pinnately and bipinnately compound leaves.
- Obovate - Reverse egg-shaped with the tip much wider than the base. Blades slightly longer than wide. Choosing "obovate" will often bring up species also described as "spatulate" and "cuneate".
- Orbicular (circular) - Blades almost circular. Blades may have indented bases like those of cordate leaves, but with rounded tips. Choosing "orbicular" will also bring up species that are both orbicular and cordate.
- Oval - (elliptical) Shaped like a somewhat flattened circle or a football with rounded ends. Refers to the shape of the blade in simple leaves and the individual leaflets in compound leaves.
- Ovate - Egg-shaped, wider at the base than the tip. Not much longer than wide. Choosing "ovate" will also bring up species that are both ovate and cordate.
- Perfoliate - Leaves where the stem apparently passes through the blade.
- Scalelike - Leaves like tiny scales without petioles.
- Spatulate - Spoon-shaped. The base of the blade widens to the wider rounded tip. Similar to cuneate and oblanceolate but with a much more rounded tip.
- Triangular (deltoid) - Triangular shaped blade with a relatively truncated base, more so than the gradually widening bases of lanceolate and ovate leaves.
- Leaf Margin
- Bipinnatifid - Pinnately (like a feather) lobed simple leaves where the primary lobes are themselves pinnately lobed. Neither the primary or secondary blade divisions reach all the way to the axes.
- Bristly - Leaf blades or leaflets with bristles (extremely thick hair-like projections) protruding from the margins.
- Ciliate - Leaf blades or leaflets with hairs attached to the margins.
- Crisped - Crumpled blade margins.
- Dentate (rounded teeth) - Margins with rounded teeth.
- Digitate - Blades with lobes arranged like the fingers of a hand.
- Dissected - Blades divided into multiple complicated fine divisions (gold poppies).
- Entire - Smooth margins.
- Lobed - Leaf blades or leaflets with lobes in no particular arrangement
- Pinnatifid - Lobes on blades or leaflets arranged in pinnate fashion (like a feather).
- Revolute - Margins curled under.
- Sawtoothed - Margins with relatively small, closely spaced, evenly spaced and sized teeth.
- Sinuate - Wavy-edged.
- Spiny - Spines, prickles, or spine-tipped teeth along the edges
- Toothed - Any kind of relatively sharp teeth.
Sonoran Desert Plant Definitions
Life Forms * Armaments * Leaves A * Leaves B
List of Plants of the Sonoran Desert