Vines and Climbing Plants of Puerto Rico and the Virgin Islands

Vines and Climbing Plants of Puerto Rico and the Virgin Islands 99
ciliate, slightly undulate, and revolute; upper
surface shiny, pubescent, scabrid, the venation
usually sunken, covered with yellowish simple
hairs; lower surface pale green, dull, with
glandular dots, pubescent or sericeous, the
venation prominent and pubescent; petioles 2-4
mm long, pubescent. Capitula of 13-22 flowers,
sessile or short-pedunculate, solitary, axillary at
the end of short and flexuous branches; involucre
campanulate, 5-9 mm high; phyllaries subulate,
the basal series smaller than the distal ones.
Corollas white or pale violet, 5-6 mm long, with
6. MIKANIA
Twining herbaceous or woody vines or less frequently erect shrubs. Stems cylindrical or hexagonal.
Leaves opposite, petiolate; blades simple; pseudostipules present or absent. Capitula homogamous,
discoid, numerous, composed of 4 flowers, arranged in spicate, paniculiform, or corymbiform, terminal
or axillary cymes; involucre cylindrical with subequal and overlapping phyllaries, subtended by a
subinvolucral bract, which is usually narrower than the phyllaries. Flowers bisexual; corollas
actinomorphic, tubular, or infundibuliform, cream-colored or white; stamens 5, the anthers connate,
exserted; ovary inferior, the style elongate, ascending, cream-colored, the apical portion with a long
sterile appendage. Fruit a usually prismatic achene with 5 ribs, brown or black; pappus numerous,
composed of bristles, without scales. A genus of about 400 neotropical species, only several in North
America and the Old World tropics. About 10% of the species are shrubby; the great majority of these
are found in the shrubby savannas of central and southern Brazil.
Key to the species of Mikania
five lanceolate to linear petals; anthers exserted;
style pubescent, bifid. Achene ca. 1.3 mm long,
conical, pubescent; pappus of bristles 5-6 mm
long and scales ca. 0.8 mm long.
Phenology: Flowering from November to July
and fruiting from February to September.
Status: Endemic to Puerto Rico, common.
Distribution: In forests and pastures of the
Cordillera Central and the zone of mogotes.
Public forests: Carite, Guajataca, Guilarte,
Maricao, Río Abajo, and Toro Negro.
1a. Pseudostipules present ....................................................................................................................... 2
1b. Pseudostipules absent ........................................................................................................................ 7
2a. Pseudostipules entire, rounded, reflexed, 8-10 mm wide; leaves thick, fragile, slightly
aromatic................................................................................................................. 3. M. fragilis
2b. Pseudostipules divided into lanceolate or filiform segments ........................................................... 3
3a. Capitula arranged in glomerules; lower surface densely covered with resinous dots. 1. M. congesta
3b. Capitula arranged in corymbs; lower surface without dots or sparsely punctate ............................ 4
4a. Involucre 3-4 mm high ............................................................................................. 4. M. micrantha
4b. Involucre 6-9 mm high ...................................................................................................................... 5
5a. Leaves pubescent on both surfaces; stems hexagonal .............................................. 2. M. cordifolia
5b. Leaves glabrous or puberulous; stems subcylindrical or obscurely angular .................................... 6
6a. Leaves coriaceous, the upper surface scabrid, the lower surface puberulous ....... 8. M. stevensiana
6b. Leaves membranaceous, glabrous ........................................................................ 5. M. odoratissima
7a. Blade of the leaves 3-6 cm long, with the venation pinnate, the margins entire ......... 7. M. porosa
7b. Blade of the leaves 5-9 cm long, with 3 main veins from the base, the margins denticulate
..................................................................................................................... 6. M. pachyphylla