A flora of Manila - Rainforestation

238
A FLORA OF MANILA
ovuled. Pod of several, rounded, flattened, finely prickly, indehiscent,
1-seeded joints. (In honor of J. Zorn, an early German physician and
botanist.)
Species 10, all of tropical America, except 2; 1, probably introduced,
in the Philippines.
1. Z. DiPHYLLA (L.) Pers.
Glabrous, the stems slender, wiry, branched, spreading or ascending from
the rather stout root, up to 40 cm in length. Leaflets 2, lanceolate, acute
or acuminate, 1 to 2.5 cm long; stipules lanceolate, produced below the
point of insertion. Racemes 2 to 6 cm long, slender, 3- to 15-flowered.
Flowers small, yellow, quite hidden by the paired, lanceolate, acuminate,
persistent bracts which are 8 to 10 mm long and tailed at the base. Pod
of 2 to 6, round, prickly joints about 2 mm wide.
In open dry grass lands, San Pedro Macati, fl. Nov.-Jan. ; of local
occurrence in the Philippines, probably introduced. Most tropical countries,
possibly originating in tropical America.
23. DESMODIUM Desvaux
Herbs, shrubs, or small trees with simple or 3-foliolate stipulate leaves.
Flowers small, white, pink, red, or purplish, in few- to many-flowered
axillary or terminal racemes or umbels, sometimes panicled. Calyx-teeth
longer or shorter than the tube, the upper two often subconnate. Corolla
exserted; standard broad; wings more or less adhering to the usually
obtuse keel. Upper stamen free or partly so, the other 9 united. Ovary
few- to many-ovuled. Pod usually composed of few to many, 1-seeded,
indehiscent, compressed joints, smooth or covered with minute hooked hairs.
(Greek "bond" or "chain," allusion to the jointed pods.)
Species 130 or more, in all tropical countries, a few in temperate regions,
30 in the Philippines.
1. Leaves 3-foliolate.
2. Bracts large, orbicular, persistent, leaf-like, enclosing and concealing
the flowers 1. D. pulchellum
2. Bracts very small or none.
3. Flowers umbellate, umbels arranged in terminal or axillary panicles;
erect shrubs 2. D. quinquepetalum
3. Flowers not umbellate; herbs or undershrubs.
4. Pods not sinuate, the segments much longer than broad.
3. D. scorpiurus
4. Pods deeply sinuate, spirally twisted, the segments as broad
as long 4. D. procumhens
4. Pods not deeply sinuate nor spirally twisted.
5. Prostrate or spreading, suffrutescent; leaves silvery-pubescent
beneath; flowers numerous 5. D. capitatum
5. Slender spreading herbs with 1 to 3 flowers in the leaf-axils.
1. Leaves 1-foliolate.
6. Pedicels usually shorter than the petioles; leaflets obovate-
cuneate, truncate or emarginate; bi'anches nearly glabrous.
6. D. triflorum
6. Pedicels longer than the petioles; leaflets usually oblong,
rounded at the apex; branches pubescent with spreading
hairs 7. D. heterophylla