Botrychium biternatum

Botrychium biternatum (Savigny) Underw.
(Latin: bi, two, and ternarius, by threes, = twice-ternate, the leaves often divided into three major parts, each of these again often divided into three parts)

Local names: sparse-lobe grape fern, southern grape fern, winter grape fern

Plant ca. 10–35 cm tall; roots usually 10 or fewer, blackish; leaves present over winter, mostly green but rarely bronze in winter if exposed; new leaves appearing in late spring to early summer; sterile blade portion green to dark green, long-stalked (stalk 3–20 cm long), ± papery/her-baceous, to 18 cm long and 28 cm wide, usually smaller, 2–3-pinnate (often 2-pinnate), the ultimate segments (= smallest subdivisions) elongate, obliquely lanceolate to narrowly lanceolate, the margins nearly parallel, finely denticulate (marginal teeth finer and more uniform than in B. dissectum), the apices obtuse to shortacuminate; 2n = 90 (Wagner & Wagner 1993). Low woods; Angelina, Bowie, Cass, Hardin (E. Whitehouse 11191), Harrison, Montgomery (V.L. Cory 50680), Nacogdoches, Newton, Sabine, Titus (all BRIT—identified J. Peck), Tyler (TEX-LL) Harris, and Liberty (Brown 2008) cos. in the Pineywoods and Brazoria Co. (Brown 2008) in the n Gulf Prairies and Marshes; se U.S. from PA s to FL w to IL, OK, and TX. Spores maturing in the fall. [B. tenuifolium Underw., B. dissectum Spreng. var. tenuifolium (Underw.) Farw., Sceptridium biternatum (Savigny) Lyon] If Botrychium is divided into segregate genera, as argued by Hauk et al. (2003), B. biternaturm would be recognized in the genus Sceptridium. This species and B. dissectum are similar morphologically and are often confused (see discussion under B. dissectum).

: Back to List :