Monterey Bay Aquarium Research Institute
Marine Botany
Phyllospadix species

There are five described species of the genus Phyllospadix: scouleri, torreyi, and serrulatus commonly found on the North American Pacific coast, and japonicus and iwatensis, on the coasts of northern Japan and eastern Korea.

Distinguishing characteristics of North American species:

  • Torreyi - (locally found in Elkhorn Slough, Asilomar state beach, Monterey Peninsula, CA) Commonly grows on less exposed areas. Generative axis has 4-6 internodes, upper 2-4 nodes bearing 1-5 pedunculate spathes, leaves are 1.5-5 mm wide. The retinaculae of the female spathes are narrow at the base while that of scouleri is not.
  • Serrulatus - (Alaska) The generative axis is reduced to single pedunculate spathe, rhizome has internodes covered with a mass of yellowish brown fibres with 2 roots, leaves have 3-7 nerves. The female spathe is obtuse, truncate or retuse. The leaftip is truncate.
  • Scouleri Hook- (from Dundas Isl, in the north to Baja California, reaching tropic of Cancer, locally in Pacific Grove, Pt. Pinos and Pt. Lobos, CA) From low intertidal to 6m deep, common in the north but in the south almost replaced by torreyi. Generative axis 0.25 -5(10)cm long, 1-2 creeping internodes with 6-10 roots, upper node bearing 1 or rarely 2 pedunculate spathes, leaves 1-4mm wide with 3 nerves : 1 in midrib to apex, two intramarginal, also cross veins. The sheath is 4-30cm long, the leaf blade 0.5-2m long. The tussock can grow up to 0.5m in diameter.
The seagrasses are herbaceous vascular plants that have such reduced vascular bundles that it is often difficult to distinguish the xylem (which transports water in plants) and phloem (which transports food). The xylem is located towards the upper epidermis in the center of the vascular bundle surrounded by the phloem which is found toward the lower epidermis.

This is a cross-section of a leaf blade. The white spaces are vacuoles and the dark circles are the vascular bundles, with xylem in the center surrounded by phloem.

surfgrass leaf cross section

Phyllospadix pages copyright Erika Marin-Spiotta 1996.
Last updated: Feb. 05, 2009