Thrinax morrisii (Leucothrinax morrisii)

Common name

brittle thatch palm, key thatch palm

Description

Stems: Solitary, erect gray stems, to 11 m tall, up to 35 cm in diameter, with obscure, incomplete leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
scars, the upper reaches covered with matted fibers and split leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
bases, and a bossboss:
expanded mass of exposed roots at the root initiation zone
of fibrous roots at the base. Leaves: Palmatepalmate:
like the palm of a hand; fan palms have palmate leaves that are usually divided into leaf segments arising from a central point, although a fan palm may have entire leaves (e.g., <em>Licuala grandis</em>)
, induplicateinduplicate:
Most palm leaflets or leaf segments are obviously folded. If the folds create a V-shape, with the midrib lower than the margins (so that rain might fall "into a valley"), the folding is induplicate.
, unarmed, with a circular blade 1-1.5 m across, divided at least half its length by numerous, lanceolatelanceolate:
term to describe leaves and leaflets that are longer than wide and widest below the mid-point; lance-shaped
segments with stiff, bifidbifid:
deeply cleft into two usually equal parts or two-lobed from the apex; for example, palms with bifid leaves or leaflet tips (e.g., <em>Chamaedorea metallica</em> has bifid leaves)
tips; petiole usually longer than the blade; leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
sheath with fibrous margins. The upper leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
surface is glossy green or glaucousglaucous:
bluish-grey or -green
; the undersurface, silvery, covered with white wax and tiny dark dot-like scales; midrib and marginal ribs prominent; transverse veinlets visible. Flowers and fruits: Inflorescenceinflorescence:
the reproductive structure of a flowering plant, including palms, consisting of flowers and associated bracts
1-1.2 m, emerging through split leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
bases, arching and branched to two orders, equal to or exceeding the leaves in length. The white flowers have both male and female parts. The fruits are small (6-8 mm in diameter), spherical and white when ripe; pedicelpedicel:
a floral stalk
less than 1 mm.

Diagnostic features

Solitary, upright palm with palmatepalmate:
like the palm of a hand; fan palms have palmate leaves that are usually divided into leaf segments arising from a central point, although a fan palm may have entire leaves (e.g., <em>Licuala grandis</em>)
leaves, the leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
blade underside silvery, leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
sheaths that split at the base and small, white fruit with very short stalk (less than 1 mm).

May be confused with

Coccothrinax species, but they have chocolate brown to purple black fruit and leafleaf:
in palms -- the leaf blade (which is usually divided into leaflets or leaf segments), the petiole (or leaf stalk) and the sheath (which forms the attachment of the leaf to the stem)
bases that do not split.

Distribution

Native to Florida and the Caribbean

Additional comments

This species is listed as endangered by the state of Florida.

Scientific name

Thrinax morrisii H. Wendl.

Now Leucothrinax morrisii (H. Wendl.) C.E.Lewis & Zona

Family

Arecaceae/Palmae

Synonyms

Simpsonia microcarpa (Sarg.) O.F. Cook

Thrinax bahamensis O.F. Cook

Thrinax drudei Becc.

Thrinax ekmanii Burret

Thrinax keyensis Sarg.

Thrinax microcarpa Sarg.

Thrinax ponceana O.F. Cook

Thrinax praeceps O.F. Cook

Thrinax punctulata Becc.