Piper, L.

Bornstein, Allan J., Smith, James F. & Tepe, Eric J., 2014, Two New Species of Piper from the Greater Antilles, Systematic Botany (Basel, Switzerland) 39 (1), pp. 10-16 : 13-16

KEY TO PUERTO RICAN SPECIES OF PIPER

1. Spikes arranged in umbellate or paniculiform clusters (3–13 spikes per group), appearing axillary; stamens 2 per flower; plants subshrubs, scarcely woody........................................................................... 2

2. Leaves rounded with peltate petiole attachment; stems, petioles, and main veins along abaxial leaf surface glabrous.............. P. peltatum

2. Leaves cordiform at base with marginal petiole attachment; stems, petioles, and main veins along abaxial leaf surface puberulent.............................................................................. P. umbellatum

1. Spikes solitary, leaf-opposed; stamens 3–6 per flower; plants distinctly woody.......................................................... 3

3. Leaves palmately veined..................................................................................................... 4

4. Leaves ciliate marginally; spikes distally curved; flowers, fruits and floral bracts forming bands around the spike; plants with anise-like odor when crushed; stems, petioles, and peduncles glabrous; petioles vaginate ca. 3 = of length; floral bracts triangular or rounded when viewed from above; stamens 4.............................. P. marginatum 4

4. Leaves glabrous marginally; spikes erect at all stages; flowers, fruits, and floral bracts not forming bands around the spike; plants lacking anise-like odor when crushed; stems, petioles, and peduncles pubescent; petioles vaginate only at very base; floral bracts cucullate; stamens 5–6................................................ P. amalago

3. Leaves pinnately veined..................................................................................................... 5

5. Flowers loosely organized along the rachis, not forming bands around the spike; fruits globose, orange to red; leaves with two pairs of major secondaries, one at very base, the other at mid-region of lamina.......................... P. blattarum

5. Flowers densely organized along rachis, forming distinct bands around the spike; fruits rounded, triangular, or rectangular, green to brown; leaves with 3 + pairs of veins................................................................ 6

6. Leaf lamina with 10–12 pairs of secondary veins that diverge along entire length of midvein; fruits rectangular (tetragonous) due to lateral compression................................................... P. swartzianum

6. Leaf lamina with 3–6 pairs of secondary veins that diverge along lower 1 = - 2 = length of midvein; 2 3 fruits rounded to triangular.......................................................................................... 7

7. Leaves smooth and completely glabrous on adaxial surface............................................................. 8

8. Petiole vaginate-winged entire length (to base of blade), the margins caducous and leaving linear scars on adaxial surface of petiole; fruits glabrous; bracts shallowly W-shaped, glabrous; prophylls 4–5 cm long.................................................................... P. glabrescens

8. Petiole vaginate at very base, lacking scar tissue; fruits apically densely pubescent; bracts triangular, short-fimbriate; prophylls 1–2 cm long.......................................... P. jacquemontianum

7. Leaves scabrous and/or pubescent adaxially (at least along the midvein)................................................. 9

9. Spikes curved distally................................................................................. P. aduncum

9. Spikes straight throughout..................................................................................... 10

10. Fruits apically densely puberulent; ovary and fruit lacking a style (stigmas sessile); anthers apically dehiscent; spikes (peduncle + rachis) 10 + cm long.................................... P. hispidum

10. Fruits essentially glabrous; ovary and young fruit with style ca. 0.5 mm long; anthers laterally dehiscent; spikes less than 8 cm long................................................ P. abajoense

KEY TO SPECIES OF PIPER WITH PALMATE LEAF VENATION FROM THE DOMINICAN REPUBLIC

1. Spikes arranged in umbellate or paniculiform clusters (3–13 spikes per group), appearing axillary; stamens 2; plants subshrubs, scarcely woody...................................................................................... P. peltatum

1. Spikes solitary, leaf-opposed; stamens 3–6; plants distinctly woody................................................................... 2

2. Petiole vaginate at least 1 = 2 of entire length, with caducous wing tissue.............................................................. 3

3. Stems, petioles, leaf lamina, bracts, and fruits densely reddish glandular (with pellucid dots) upon drying; inflorescence rachis densely white-pubescent; fruits oblong-elliptic with distinct style; flowers, fruits, and bracts not forming bands around the spike...................................................................... P. oviedoi

3. Stems, petioles, leaf blades, bracts, and fruits lacking glands (pellucid dots) upon drying, or if present, translucent, not reddish; inflorescence rachis glabrous; fruits round or tetragonous; flowers, fruits, and bracts forming bands around the spike............................................................................... 4

4. Leaves ciliate marginally; spikes distally curved; plants with anise-like odor when crushed; stems, petioles, and peduncles glabrous; floral bracts densely fimbriate; fruits rounded................................. P. marginatum

4. Leaves glabrous marginally; spikes straight at all stages; plants lacking anise-like odor when crushed; stems, petioles, and peduncles tomentose; floral bracts hirsute; fruits tetragonous................................... P. picardae

2. Petiole vaginate only at very base, lacking wing tissue............................................................................ 5

5. Leaves membranous to chartaceous with 5–7 primary veins; fruits brown to black............................................... 6

6. Leaves hirsutulous along main veins below; inflorescences with flowering segment 0.5–1.5 cm long, borne on filiform peduncle; fruits depressed globose, lacking a style................................................. P. buchii

6. Leaves glabrous or puberulent below; inflorescences with flowering segment 3 + cm long, borne on stout peduncle; fruits ovoid, evidently stylose.......................................................... P. amalago

5. Leaves coriaceous with 3 primary veins; fruits white......................................................................... 7

7. Flowers closely spaced along inflorescence axis; rachis densely white-pubescent; flowers sessile, but fruits with pseudo-pedicel (developing upon fruit maturation); pseudo-pedicel 1.5–2 mm long, 2.5–3.5 mm wide, densely white-pubescent; fruits> 5 mm wide, densely white-pubescent; stigma lobes narrow, <0.25 mm wide....................................................................... P. samanense

7. Flowers widely spaced along inflorescence axis; rachis puberulent; flowers and fruits with true pedicels; pedicels 1.3–4.2 mm long (M = 2.66), 0.5–1.2 mm wide, puberulent; fruits <4 mm wide, glabrous to puberulent; stigma lobes broad, 0.4–0.75 mm wide.................................................. P. claseanum