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Ferns of the Sierra (1960) by Robert J. Rodin


SELAGINELLACEAE
SELAGINELLA FAMILY

SELAGINELLA

Low creeping branching herbaceous plants, usually on soil, having the appearance of moss. Stems covered with small uniform leaves which overlap. Leaves spirally attached to the stem. Reproduction by spores borne in cones, the cones usually quadrangular whereas the vegetative stems are not quadrangular but cylindrical.

The vegetative leaves and spore bearing leaves are rather similar in appearance. Cones, therefore, resemble portions of a leafy stem. For this reason, and because cones are not borne on stalks, one must examine a plant carefully in order to see them. Cones produce two types of spores: microspores, small, numerous, usually red or orange, and megaspores, 4 per sporangium, frequently yellow. Margins of leaves and sporophylls may bear hair-like cilia, and the leaf apex often terminates in a seta, a soft bristle, white or transparent.

The only genus in the family, it is widely distributed throughout the world, and is more common in the tropics and places of high rainfall. Species from Texas and other areas may be bought in variety stores as the Resurrection Plant, which appear dead and are tightly curled, but if put into a saucer of water overnight, they open and become bright green. Our species are not usually suitable for gardens or as potted house plants. They will stay for short periods if kept in moist soil. Invert a quart jar over them for best results.

KEY TO THE SPECIES:

Branches somewhat dorsiventral, leaves of the under ranks largest, obliquely imbricate, foothills to 6000 feet elevation S. hansenii
Branches not dorsiventral, leaves uniform, equally distributed on all sides, 8,000 to 11,000 feet elevation S. watsonii

HANSEN’S SELAGINELLA

Selaginella hansenii Hieron. (Fig. 53)

S. ruprestris var. hanseni

Prostrate stems 2 to 10 inches long, stems branch once, rarely 2 or 3 times, strongly dorsiventral with leaves obliquely imbricate. Leaves lanceolate, terminating in a seta which is about 1/32 inch long, white to transparent. Leaf margins are lined with 6 to 18 cilia on each side. In cones the sporophylls broader than leaves, almost triangular, with sporangia attached at the base, megaspores yellow, microspores orange.

Forms mats on rocky places at lower elevations in the Sierra Nevada from 1,000 to 6,000 feet elevation. Common in the foothills, this species may be observed at the base of the cliffs on the talus slope on the north side of Yosemite Valley. It extends from Fresno County to Mount Shasta.

ALPINE SELAGINELLA

Selaginella watsonii Underw. (Fig. 53)

Creeping stems 1 to 12 inches long with a few short branches that form mats. Lanceolate leaves are of equal length on upper and lower sides of the stem. Each leaf has as many as 9 cilia or none, ending with a short, greenish-yellow seta. Cones quadrangular 1/2 to 1 inch long in which sporophylls resemble leaves except that sporophylls are broader, almost triangular.

Although this species has on rare occasions been found at 6,000 feet elevation, it is usually found from 10,000 to 13,000 feet. Known from alpine regions on some of the higher mountains in the Sierra from such places as Fairview Dome, Snow Mountain, Mt. Lyell Cirque, and Kuna Crest in Yosemite. It was first collected in Utah and has also been recorded from Nevada, Oregon, and Montana.


Fig. 53 HANSEN’S SELAGINELLA (Selaginella hansenii). ALPINE SELAGINELLA (Selaginella watsonii)
[click to enlarge]

Fig. 53 HANSEN’S SELAGINELLA (Selaginella hansenii.) Upper: Found at low elevations. White arrows point to quadrangular cones. Lower: ALPINE SELAGINELLA (Selaginella watsonii). Growing in cracks of mica schist rocks above 10,000 feet elevation.



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