Native plant identification key for the
Palos Verdes Peninsula, California

Vines

• Lianas or woody vines
  • Leaves compound (divided into separate leaflets)
    • Leaves pinnately divided (leaflets diverge from the rachis or central axis)
      • Leaves 3-foliate (sometimes 5); leaflets ovate; margins crenulate (sometimes lobed) toward tip; terminal leaflet ~1-13 cm long, ~1-8 cm wide; side leaflets ~1-7 cm long, ~1-6 cm wide; shiny-glabrous on top, slightly hairy underside; bright green in spring, darker green in summer, red or splotchy red and green in fall, winter deciduous; liana, erect shrub, or small tree = Toxicodendron diversilobum (poison oak)
• Herbaceous vines (non-woody, tender stems and tendrils)
  • No leaves or tiny scale-like leaves <2 mm long; plants are non-photosynthetic but parasitical, so they don't need leaves; and stems are, therefore, the visually dominant part of the plant, forming net-like coverings on host plants
    • Stems very slender and pale yellow = Cuscuta pentagona (western field dodder)
    • Stems medium thickness, bright greenish-yellow or bright orange = Cuscuta californica (chaparral dodder)
  • Leaves simple (not divided into separate leaflets, though they may be lobed)
    • Leaves opposite (pairs of leaves coming out of the same node) low on the stem but alternate (single leaves on different sides of the stem from their neighbors) higher up
      • Leaves ovate, blunt-tipped; entire; ~0.5-2 cm long; crowded below, each leaf on a distinct petiole opposite its neighbor; higher up, leaves are alternate, sessile, slimmer, longer; glabrous; bright to medium green = Antirrhinum kelloggii (Kellogg's snapdragon)
    • Leaves alternate (single leaves on different sides of the stem from their neighbors) throughout
      • Leaves deltoid-hastate (triangular but lobed), 3-lobed, lobes about equal in size, broad; margins mostly entire but basal lobes have 2-3 teeth at tips, terminal lobe tapers to 1 tip; ~4-13 cm long; petioles about as long as leaves; dark green/greyish green; glabrous to densely woolly; thick, nearly fleshy = Calystegia macrostegia (California morning glory)
      • Leaves lance-hastate (triangular but with lanceolate lobes much longer than wide), 3-lobed, all roughly equal in size, each lobe ~1.5-2 cm long and ~0.5-1 cm wide, basal lobes with 2 teeth, central lobe 1 acute tip; petioles ~0.5-2 cm long; bluish-green, glabrous (smooth-surfaced) and glaucous (covered with a whitish resin or dust) = Calystegia peirsonii (Peirson's morning glory)
      • Leaves triangular-ovate (egg-shaped), base somewhat cordate (heart-shaped); strong, nauseous smell; leaves ~10-30 cm long, held erect on petioles; blue-grey green; coarsely scabrous/scaly; margins lightly serrate, may be somewhat lobed at base = Cucurbita foetidissima (calabazilla)
      • Leaves orbicular (round) or cordate (heart-shaped), palmately 5-7 lobed (diverging from a common base), on a petiole ~3-8 cm long; ~5-10 cm long; light to medium green; lightly pubescent (hairy/downy) or glabrous (smooth- surfaced) = Marah macrocarpus (Cucamonga manroot)
  • Leaves compound (divided into separate leaflets)
    • Leaves pinnately compound (leaflets diverge from along the rachis or central axis of the compound leaf). Leaves even-divided, with 8, 10, or 12 leaflets, with stipules (small leaf-like appendages) at base of petiole connecting the compound leaf to the stem; oblong-lanceolate (much longer than wide, with margins parallel to one another below tip and above base) to elliptical (symmetrical oval); medium green; ~2-3.5 cm long; very short pedicelled; from a distance, each pair of leaflets looks opposite, but closer inspection shows each pair to be alternate with a small offset; margins entire; tip mucronate (with a small pointed tip); end of rachis forms a twisting tendril = Lathyrus vestitus (Pacific pea)

First placed on web: 08/01/11
Last revised: 08/16/11
Christine M. Rodrigue, Ph.D., Department of Geography, California State University, Long Beach, CA 90840-1101
rodrigue@csulb.edu

The development of this key was partially funded through the Geoscience Diversity Enhancement Program (Award #0703798) and through a course of re-assigned time provided by the CSULB Scholarly and Creative Activities Committee. Thanks also to the students in sections of biogeography, introductory physical geography, GDEP, and LSAMP for "test-driving" various editions of this key.