acicular

adj. slender and pointed, needle-shaped

In botany, the following terms are used to describe the shape of plant leaves:Acicular (acicularis): Slender and pointed, needle-likeAcuminate (acuminata): Tapering to a long pointAristate (aristata): Ending in a stiff, bristle-like pointBipinnate (bipinnata): Each leaflet also pinnateCordate (cordata): Heart-shaped, stem attaches to cleftCuneate (cuneata): Triangular, stem attaches to pointDeltoid (deltoidea): Triangular, stem attaches to sideDigitate (digitata): Divided into finger-like lobesElliptic (elliptica): Oval, with a short or no pointFalcate (falcata): sickle-shapedFlabellate (flabellata): Semi-circular, or fan-likeHastate (hastata): shaped like a spear point, with flaring pointed lobes at the baseLance-shaped, lanceolate (lanceolata): Long, wider in the middle Linear (linearis): Long and very narrowLobed (lobata): With several pointsObcordate (obcordata): Heart-shaped, stem attaches to tapering pointOblanceolate (oblanceolata): Top wider than bottomOblong (oblongus): Having an elongated form with slightly parallel sidesObovate (obovata): Teardrop-shaped, stem attaches to tapering pointObtuse (obtusus): With a blunt tipOrbicular (orbicularis): CircularOvate (ovata): Oval, egg-shaped, with a tapering pointPalmate (palmata): Divided into many lobesPedate (pedata): Palmate, with cleft lobesPeltate (peltata): Rounded, stem underneathPerfoliate (perfoliata): Stem through the leavesPinnate (pinnata): Two rows of leafletsodd-pinnate : pinnate with a terminal leafletparipinnate, even-pinnate : pinnate lacking a terminal leafletPinnatisect (pinnatifida): Cut, but not to the midrib (it would be pinnate then)Reniform (reniformis): Kidney-shapedRhomboid (rhomboidalis): Diamond-shapedRound (rotundifolia): CircularSagittate (sagittata): Arrowhead-shapedSpatulate, spathulate (spathulata): Spoon-shapedSpear-shaped (hastata): Pointed, with barbsSubulate (subulata): Awl-shaped with a tapering pointSword-shaped (ensiformis): Long, thin, pointedTrifoliate, ternate (trifoliata): Divided into three leafletsTripinnate (tripinnata): Pinnately compound in which each leaflet is itself bipinnateTruncate (truncata): With a squared off endUnifoliate (unifoliata): with a single leaf
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Adjective
1. narrow and long and pointed; as pine leaves
(synonym) acerate, acerose, needle-shaped
(similar) simple, unsubdivided

(a.)
Needle-shaped; slender like a needle or bristle, as some leaves or crystals; also, having sharp points like needless.
  

bot. acicular