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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

ISOETES QUILLWORT
(Greek: evergreen, from habit of some species) Perhaps most poorly known lycophyte genus. Mature female spores, found in decaying leaf bases or soil, critical for identification, as are hand lens for texture when dry, microscope with micrometer for size. Hybrids (spores of variable size, shape) common between aquatic species, making them less distinct.

Key to Isoetes

1. Plant terrestrial (or becoming so), of seasonally wet soil, lake margins, temporary streams, vernal pools; generally < 1500 m

2. Translucent membrane covering < 75% of sporangium ..... I. howellii

2' Translucent membrane covering > 75% of sporangium

3. Plant of wet soil; leaf generally > 8 cm, > 1 mm wide at middle, rigid, ± brittle ..... I. nuttallii

3' Plant of vernal pools; leaf generally < 8 cm, < 1 mm wide at middle, soft, flexible ..... I. orcuttii

1' Plant underwater in persistent lakes or pools; generally > 1500 m

4. Female spores prickly ..... I. echinospora

4' Female spores ridged or tubercled

5. Leaf abruptly tapered to tip; female spore 0.3–0.5 mm diam ..... I. bolanderi

5' Leaf gradually tapered to tip; female spore 0.5–0.7 mm diam ..... I. occidentalis

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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