Dichanthelium androsense, LeBlond & Sorrie, 2024

Dichanthelium androsense ( Poaceae ), a new species from Andros Island in the Bahamas.

Six collections from four populations of an unusual Dichanthelium taxon not matching any species or section recognized by Freckmann and Lelong (2003) were made from North Andros Island in the Bahamas in 1992 and 1993 ( Sorrie &LeBlond, 1997).

Dichanthelium androsense LeBlond & Sorrie , sp. nov. ( Fig. 20 View FIG ). TYPE: THE BAHAMAS: North Andros District: wet Pineland off NE side of a connector road heading NW towards Main Lumber Road from Queen’s Highway at a point 8.7 mi S of the North Andros airport,lat.24.9353, long.–78.0409; 6 May 1993, LeBlond 3266, Sorrie, & Weakley (HOLOTYPE: NCU), Sorrie 7220, LeBlond, & Weakley (ISOTYPE: US) .

Diagnosis.— Dichanthelium androsense superficially resembles D. acuminatum var. acuminatum with its small spikelets, ciliate blades and overall pubescence, but differs from it and all other known Dichanthelium taxa by a combination of its short, bushy ligule and the absence of a pseudoligule; glabrous to glabrate spikelets; shiny and often glandular to stipitate-glandular glumes and lower lemma; and sheath papillae that are distinctly red-orange and swollen in situ (this character lost in drying).

Description.— 1–several culms together, cespitose, nonrhizomatous. Culms to 40 cm, slender, 0.4–1.1 mm in diameter at lowest elongate internode; internodes moderately pilose or papillose-pilose with hairs 0.5–2 mm long; nodes, especially lower, bearded with retrorse hairs (hairs of the nodes and internodes often lost as specimens age). Rosette leaves 1.5–3 cm long × 3-5 mm wide, moderately-densely pubescent abaxially, sparsely pubescent adaxially, margins ciliate. Culm leaf sheaths half or less as long as internodes, moderately pilose to papillose-pilose with variably spreading hairs (0.5–) 1–2 mm long ( in situ , sheath papillae are

distinctively red-orange and swollen, but this character is lost in drying). Ligule cilia bushy, 0.5–0.8(–1.3) mm long, membranous portion minute or absent, without a distinct pseudoligule. Blades 2–5.5 cm long × 2-5 mm wide, usually ciliate distally as well as proximally, moderately to sparsely pilose adaxially with appressed hairs, moderately densely papillose-pilose abaxially with non-appressed hairs. Vernal panicles ± 3 cm long × 1.5 cm wide (few seen, these senescent), rachis sparsely pilose with spreading hairs to 0.3 mm long; rachis, branches, and pedicels minutely scabrous. Spikelets elliptical, obtuse, (1.4–)1.5–1.6(–1.7) mm long, the glumes and lower lemmas shiny, sometimes glandular to stipitate-glandular, glabrous to sparsely puberulent; lower glumes 0.5–0.6(–0.7) mm long, obtuse to broadly acute; upper glumes and lower lemmas equaling upper lemmas. Autumnal sheaths and blade abaxial surfaces densely (-sparsely) pubescent with spreading hairs 0.2–0.5 mm long; autumnal panicle indumentum similar to vernal. None of the vegetative features can be described as velvety-pilose. Etymology.— The taxon was determined to be distinct by examining plants collected on North Andros Island in The Bahamas, and only known from that island as of this accounting.

Additional collections (paratypes). THE BAHAMAS. North Andros District: wet Pineland off west side of Main Lumber Road N of junction with SE-NW connector road from Queen’s Highway , 15 Mar 1992, LeBlond 2666 & Sorrie ( FTG); same location, 4 May 1993, LeBlond 3250, Sorrie, & Weakley ( MO); N side of Cross Creek and W side of Main Lumber Road 2.4 mi N of junction with SE-NW connector road from Queen’s Highway, 4 May 1993, Sorrie 7202, LeBlond, & Weakley ( FLAS); marsh/pineland ecotone near wellfield SW of Nichols Town, off road to Red Bays , 7 May 1993, LeBlond 3272, Sorrie, & Weakley ( FSU) .