Guide to Liverworts of Oregon: Asterella saccata (Wahlenb.) Evans
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1a sex organs on primary thallus Asterella 2b monoicous; spores <100μm > Asterella 3b spores brown or purple > Asterella 4b spore and elaters brown > Asterella saccata
Synonym: None.
Special status: None; listing appropriate if Oregon record is verified.
Recognition: Distinguished from other species (Schumacker & Vana, 2005) by ventral scales projecting beyond thallus apex. The spores of this species have a micro-reticulate pattern reminiscent of A. californica but the spores of Asterella saccata are less than 100 μm while the spores of A. californica are much larger than 100 μm.
FNA description:
Plants green above, purplish along margins and underneath, the thalli curl upward around apical margins exposing white scale appendages, forming a conspicuous apical tuft; branching dichotomous, ventral intercalary branches infrequent. Thalli 5--10 x 2--3 mm; epidermis smooth, cells 20 x 30 μm with slightly thickened walls and small trigones; air pores indistinct, surrounded by 1--3 tiers of 5--7 scarcely differentiated cells, oil cells few, scattered; ventral scales deep purple, long tapered, with scattered oil cells; appendages 1--2, white, long tapered lanceolate to acuminate, as long or longer than scales, curling up around the anterior thalli margins, forming conspicuous white clusters at apices. Sexual condition paroicous, occasionally autoicous; androecia form ill‑defined dorsal streaks of papillae at posterior bases of gynoecial stalks or on nearby branches; gynoecia terminal on main thalli, stalks 1--2 cm, purplish with cluster of white hairlike scales at bases and none at apices; carpocephala 2--3 mm across, ovate, at least 1-‑1/2 times taller than wide with 3--4 lobes directed downward; pseudoperianths conical, of 6--8 white segments, connate at apices. Sporophyte capsules yellowish; spores yellow to pale brown, 80--90 μm; elaters yellowish, 1--3-spiral, 150--200 μm. (Whittemore 2023)
Distribution: On soil at high elevations; reported by Frye and Clark (1937) from Crater Lake and Cornucopia.
Comments: The reports of Frye and Clark are notoriously unreliable; the Cornucopia record is more likely correct; the Crater Lake one is suspect. Both need re-examination.
Idaho. Coll. J.B. Leiberg.
Idaho. Coll. J.B. Leiberg.