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
- 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.
Phyllospadix pages copyright Erika