Isoëtes lithophila
Ann. Missouri Bot. Gard. 9: 135. 1922.
Common names: Rock quillwort
Treatment appears in FNA Volume 2.
Revision as of 20:24, 5 November 2020 by imported>Volume Importer
Plants becoming terrestrial. Rootstock nearly globose, 2-lobed. Leaves deciduous, bright green, pale toward base, spirally arranged, to 12(–20) cm, pliant, gradually tapering to tip. Velum covering entire sporangium. Sporangium wall unpigmented. Megaspores light gray to gray-brown, 290–360 μm diam., obscurely rugulate with low ridges; girdle obscure. Microspores brown in mass, 30–33 μm, tuberculate to spinulose. 2n = 22.
Phenology: Spores mature in winter or spring.
Habitat: Shallow depressions on granite outcrops
Discussion
Isoëtes lithophila is known from granite outcrops in Burnett, Mason, and Llano counties in south central Texas.
Of conservation concern.
Selected References
None.
Lower Taxa
None.