RUTACEAE/CITRUS 489 - 35. ORCHIDACEAE/SCAPHYGLOTTIS 301

AMARANTHUS L

67. RUTACEAE/CITRUS 489

KEY TO THE GENERA OF RUTACEAE

Flowers more than 10 mm long; stamens numerous; fruits large, fleshy, with many seeds; leaves appearing simple; plants cultivated trees in the Laboratory Clearing Citrus Flowers less than 5 mm long; stamens 4 or 5; fruits of 1-5 follicles each dehiscing on one side with

a single shiny seed; leaves pinnately compound; plants large forest trees Zanthoxylum Seeds of most Zanthoxylum are well suited for bird

dispersal, but those of Z. procerum are apparently auto- chorous, being released by the hydroscopic contractions of the inner wall of the follicle. The same inner wall is used in other species to project the shiny black seed out of the follicle, where it may be displayed on the pendent funicle. Other animals, such as monkeys, may also play an important role in dispersal of Zanthoxylum. Howler and white-faced monkeys are reported to take the seeds (Oppenheimer, 1968; Hladik & Hladik, 1969). Citrus species are eaten by spider monkeys (Hladik & Hladik, 1969) and no doubt by other mammals as well.

About 150 genera and over 1,500 species; widely dis- tributed in warm regions, most numerous in South Africa and Australia.

CITRUS L.

Citrus aurantifolia (Christman) Swingle, J. Wash.

Acad. Sci. 3:465. 1913 Lime, Limon, Limon verde

Shrub or tree, 2-8 m tall, glabrous, usually with numerous axillary spines 5-17 mm long. Leaves simple; petioles oblanceolate-winged, 5-28 mm long, 2-9 mm wide, articulated at apex; blades ovate to ± elliptic, acute to bluntly acuminate at apex (the acumen sometimes emarginate), obtuse to rounded at base, 4-13 cm long, 2-6 cm wide, crenate. Flowers solitary to few, in short corymbose cymes, (4) 5-parted; pedicels 3-5 mm long; calyx shal- lowly 4- or 5-lobed; petals white, oblong-lanceolate,

11-14 mm long, 3-5 mm wide; stamens 20-25; filaments 4-6 mm long, connate into small clusters; anthers 2-3 mm long; disk ca 1 mm high; ovary obovoid, 2-3 mm long; style 2-3 mm long, soon deciduous; stigma sub- globose. Fruits ellipsoid at maturity, 3.5-6 cm diam, mammillate at apex, green to yellow, sour, the core solid.

Croat 9190,14945.

Cultivated at the Laboratory Clearing; reported by Standley (1933) to be naturalized at some places on the island. Flowers mostly during the dry season. The fruits mature mainly in the rainy season.

Native apparently to East Pakistan, Assam, Burma, Thailand, and Malaysia; now widely cultivated in the tropics and subtropics and throughout Panama.

Citrus aurantium L., Sp. PL 782. 1753 Sour orange, Seville orange

Tree, 3-6 m tall, unarmed or the few axillary spines to 5 mm long. Leaves simple, glabrous; petioles broadly winged at apex, 14-27 mm long, usually 10-15 mm wide, narrowed to an almost wingless base, articulated at apex;

blades broadly elliptic to obovate, bluntly acuminate and

± emarginate at apex, cuneate at base, 5-12 cm long, 3-7.5 cm wide, crenate. Flowers 5-parted, solitary in axils; pedicels puberulent, 9-11 mm long in fruit; calyx puberulent, the lobes ca 2 mm long; petals white. Fruits globose, 4-6 cm diam, depressed or flattened at apex, orange, sour, the core hollow. Croat 9184, 14944.

Cultivated at the laboratory but uncommon. Flowers in the dry season. The fruits mature in the rainy season.

KEY TO THE SPECIES OF CITRUS

Petioles broadly winged, the wings oblanceolate to apically broadened, 2-15 mm wide:

Fruits 10 cm or more diam; petioles and lower surface of blades sparsely pubescent (at least on

. veins) C. grandis (L.) Osbeck

Fruits less than 8 cm diam; petioles and lower surface of blades glabrous:

Petiole wings oblanceolate, 2-9 mm wide; branchlets usually with numerous axillary spines 5-17 mm long; mature fruits ellipsoid, mammillate apically, green to yellow, the core

s°lid C. aurantifolia (Christman) Swingle

Petiole wings apically broadened, mostly 10-15 mm wide; branchlets usually spineless, or the few spines 5 mm long or less; mature fruits globose, depressed or flattened apically, orange to red, the core hollow C. aurantium L.

Petioles narrowly winged or narrowly margined, the wings usually 2 mm wide or less (rarely wider in C. sinensis):

Branchlets usually spineless; mature fruits depressed-globose, green to orange or reddish- orange, the peel easily separating from the segments C. reticulata Blanco Branchlets usually with at least a few axillary spines; mature fruits globose or ovoid, the peel not

easily separating from the segments:

Petioles winged; axillary spines few, 5 mm long or less; mature fruits globose, flattened or depressed apically, yellow-green to orange, sweet C. sinensis (L.) Osbeck Petioles margined; axillary spines usually many, to 27 mm long; mature fruits ovoid, mammil-

late apically, light yellow, sour C. limon (L.) Burm.f.

490 DICOTYLEDONEAE

Native apparently to East Pakistan, Assam, Burma, and adjacent southwestern China; now widely cultivated in the tropics and subtropics and throughout Panama.

Citrus grandis (L.) Osbeck, Dagbok Ofwer Ostin. Resa 98. 1757

Shaddock, Pummelo

Tree, 3-10 m tall, unarmed or bearing axillary spines;

twigs pubescent. Leaves simple; petioles broadly obcordate-winged, articulate at apex; blades oval to broadly ovate, rounded to retuse at apex (bluntly pointed on young shoots), 8-20 cm long, 6-15 cm wide, sparsely pubescent at least on veins below. Flowers 5-parted, solitary or usually clustered in axils, 2-2.5 cm long, very fragrant; petals white, broad; stamens 20-25; ovary globose; style columnar; stigma large, capitate. Fruits globose or depressed-globose, 10-15 cm diam, smooth, pale yellow, sour; segments ca 12. Croat 4210.

Cultivated in the Laboratory Clearing between the dock and the boathouse, now engulfed in secondary vegetation. Seasonal behavior unknown.

Native to southeastern Asia and India; now widely cultivated in the tropics.

Citrus limon (L.) Burm.f., Fl. Ind. 173. 1768 Lemon

Tree, to 6 m tall, glabrous, heavily armed with axillary spines 5-27 mm long. Leaves simple; petioles narrowly margined, 5-7 mm long, ca 2 mm wide, articulate at apex; blades elliptic to oval, rounded to bluntly acuminate at apex, widely cuneate at base, 4-11 cm long, 1.5-6 cm wide, crenate. Flowers 5-parted, solitary or clustered in axils, 8-17 mm long; petals pinkish outside, white inside;

stamens 20 or more; ovary tapered at apex. Fruits oblong to ovoid, 5-10 cm long, mammillate at apex, light yellow, somewhat roughened, sour; segments 8-10. Croat 10767.

Occasional; cultivated at the Laboratory Clearing.

Seasonal behavior not determined.

Apparently native to northeastern India, Bangladesh, northern Burma, and southern China; now widely cultivated in the tropics and subtropics and throughout Panama.

Citrus reticulata Blanco, Fl. Filip. 610. 1837 Tangerine, Mandarin orange

Tree, to 8 m tall, glabrous, unarmed; stems prominently ribbed below petioles. Leaves simple; petioles narrowly winged near apex, 6-14 mm long, ca 2 mm wide, articulate at apex; blades ovate to elliptic, blunt to retuse at apex, obtuse to acute at base, 3-8.5 cm long, 1.5-4.5 cm wide, densely punctate, ± stiff, bicolorous, subentire to crenate. Flowers strongly aromatic, 5-parted, solitary (or paired) in axils; calyx short, thick, lobed to about middle, with prominent submarginal bumps, the margin thin, often minutely ciliolate; petals oblong-obovate, acute to rounded at apex, white, spreading at anthesis, 11-14 mm long, ca 3 mm wide, with sparse, large, glandular dots; stamens ca 20, ± unequal, 8-10 mm long, the filaments weakly fused laterally; anthers oblong, the connective prolonged into a greenish knob; pollen

yellow-golden, tacky, adhering in large clusters; ovary depressed-globose, glabrous; disk prominent; style shorter than stamens; stigma globose. Fruits depressed- globose, 3-3.5 cm diam, orange at maturity, sweet, the rind easily separating. Croat 14579.

Common; cultivated in the Laboratory Clearing.

Flowers throughout the dry season and the early rainy season. The fruits mature in the late dry season and in the rainy season.

Flowers are visited by hummingbirds.

Apparently native to Indochina; now widely cultivated in the tropics and subtropics and throughout Panama.

Citrus sinensis (L.) Osbeck, Reise Ostind. China 250.

1765

Sweet orange, Orange, Naranja

Shrub or tree, to 8 m tall; axillary spines few, 2-5 mm long. Leaves simple; petioles usually with a narrow, oblanceolate wing 6-18 mm long and 1-2(5) mm wide, articulate at apex; blades ± elliptic, acute or obtuse and retuse at apex, cuneate at base, 3.5-9 cm long, 1.5-4.5 cm wide, crenulate. Flowers solitary in axils, 5-parted;

pedicels 7-12 mm long in fruit; calyx to 6 mm diam, the lobes acute, ciliate, to 2 mm long; petals white. Fruits globose, 4-12 cm diam, yellow-green to orange, sweet, the rind not separating easily from segments. Croat 10765.

Occasional; cultivated in the Laboratory Clearing.

Flowers in the dry season. The fruits mature in the rainy season.

Apparently native to Bangladesh, northern Burma, southeastern China, and Indochina; now widely cultivated in the tropics and subtropics and throughout Panama.

ZANTHOXYLUML.

Zanthoxylum belizense Lund., Contr. Univ. Michigan Herb. 6:35. 1941

Arcabu, Tachuelo

Dioecious tree, 13-30 m tall, to almost 1 m dbh; trunk of younger trees armed, the prickles large, corky, horizontally flattened, to ca 5 cm wide and 1 cm thick (somewhat rounded and numerous on juvenile plants), generally deciduous on older trees, the scar often visible; branches and branchlets with ribs extending downward from petioles and with occasional small conical prickles; outer bark thin, brown, sparsely stellate-pubescent. Leaves pinnate, generally imparipinnate or the terminal pair bearing the scar of an aborted terminal leaflet (occasionally with 1 leaflet merely appearing terminal), 16-67 cm long; petioles mostly 5-10 cm long, sparsely stellate- pubescent; leaflets 8-20(26), subopposite to alternate, oblong-elliptic to oblong, abruptly acuminate, acute to obtuse at base, 4.5-16(21) cm long, 1.5-5.5 (7) cm wide, sessile or obscurely petiolulate, pellucid-punctate, ± entire and revolute on margin, dark green, shiny and sparsely stellate-pubescent above, duller and densely pubescent below, the trichomes stellate, mostly sessile;

juvenile leaves as much as 1.5 m long, the leaflets 22 cm long and 7.5 cm wide. Panicles terminal and upper-

67.

RUTACEAE/ZANTHOXYLUM

491

KEY TO THE SPECIES OF ZANTHOXYLUM Leaves densely pubescent on lower surface:

Trichomes stellate; corky prickles on trunk flattened, horizontally oriented Z. belizense Lund.

Trichomes unbranched; corky prickles on trunk rounded in outline, somewhat vertically oriented Z. setulosum P. Wils.

Leaves glabrous or minutely pubescent on lower surface:

Petals 3; follicle 1, the valves deciduous; leaflets equilateral and ± decurrent at base, markedly pellucid-punctate on margin, otherwise opaque, both surfaces densely lepidote, the underside glabrous, lacking prickles Z. procerum Donn. Sm.

Petals 5; follicles 3 or 4 (rarely 2), the valves persistent; leaflets inequilateral at base, not decurrent, pellucid-punctate all over, lacking lepidote scales, the underside often minutely puberulent, often bearing 1 or 2 long prickles Z. panamense P. Wils.

axillary, 15-33 cm long, widely branched, the branches and pedicels sparsely stellate-pubescent; branchlets scaly, the scales deltoid, ciliate; pedicels to 1.5 mm long; calyx triangular, ciliate; flowers unisexual, greenish-white, 5-lobed, to 3.7 mm wide; petals ± elliptic, acute, imbri- cate, 1.4-3.3 mm long; stamens 5, alternate, broadly exserted, to 4 mm long in staminate flowers, shorter and sterile in pistillate flowers; ovary 5-lobed, pubescent;

style short; stigma simple. Fruits of 1 or 2 globose follicles, 3.5-5 mm long, punctate-verrucose; seeds dark brown, shiny, somewhat shorter than follicle. Croat 12497.

Occasional in the forest, though sometimes locally abundant in older forest. Flowers from August to Octo- ber; individual plants may flower for at least a month.

The fruits mature from January to March. Leaves fall off in the dry season, but the new ones all grow out before flowering begins.

Southern Mexico to Panama and possibly Colombia.

In Panama, known from tropical moist forest in the Canal Zone, Colon, and San Bias, from premontane wet forest in Colon (Santa Rita Ridge), and from tropical wet forest in Colon (Icacal).

See Fig. 296.

Zanthoxylum panamense P. Wils., Contr. U.S. Natl.

Herb. 20:479. 1922

Arcabii, Acabii, Alcabu, Prickly holly, Prickly yellow, Lagarto

Medium to large, dioecious tree, to 28 m tall; trunk to 75 cm dbh, buttressed to ca 1.5 m, armed, the prickles conical, corky, the base to 3.5 cm long, the apex somewhat flattened laterally, deciduous from older trunks at base, persistent above and on branches (especially the smaller ones); outer bark thin, not deeply fissured, often very roughened; inner bark thick, tan, granular, flaking upon slash; twigs puberulent, the trichomes appressed or uncinate; sap usually bitter, not noticeably aromatic.

Leaves alternate, compound, imparipinnate or rarely paripinnate, mostly 15-60 cm long; petioles minutely puberulent, mostly 3-9 cm long, the basal pulvinus pro- nounced; rachis often canaliculate above, broadly so below leaflets, glabrous to minutely puberulent, sometimes armed; petiolules 3-5(7) mm long; leaflets 10-20, opposite to subopposite, sometimes alternate especially basally, mostly ± oblong-elliptic, abruptly acuminate (the acumen sharp or blunt), rarely rounded at apex,

rounded or cuneate and usually inequilateral at base (except terminal leaflet), 4-19 cm long, 1.5-7 cm wide, entire or obscurely crenulate, glabrous above or inconspicuously puberulent especially on midrib, glabrous or with inconspicuous, short, appressed trichomes below, occasionally bearing 1 or more, long, sharp prickles on midrib beneath, both surfaces shiny, with small and numerous pellucid dots (sometimes obscure before dry- ing), sometimes with a few much larger, plate-shaped glands on both surfaces. Panicles terminal, 20-30 cm long (shorter on pistillate plants), highly branched, the branches densely hispidulous; pedicels ca 1 mm long;

flowers unisexual, white or greenish, 5-parted; calyx puberulent, the lobes short, acute to rounded; petals

± elliptic, acute at apex, 1.5-3 mm long, to 1 mm wide;

staminate flowers with stamens 5, exserted, the filaments ca 3 mm long, alternating with lobes of pistillode, the anthers oblong, the pistillode minutely pubescent; pistillate flowers lacking stamens, the ovary broadly obovoid, 3- or 4-lobed, to 1.5 mm long, glabrous and glandular- dotted, the styles (2)3, the stigmas broadly discoid, nearly sessile, round or obtusely 3-sided, more than three- fourths as broad as ovary. Fruits of usually 3 or 4 brown follicles, each 6-8 mm long, puberulent, dehiscing from an apical, medial suture, the valves persistent; seeds 1 per follicle, shiny, black or dark brown, 3-5 mm long, suspended from capsule on a tough fiber. Croat 6249 and 12574 (large-leaved form), 14885 and 16589a (small- leaved form).

Occasional, especially in the young forest. Flowers from April to October, mostly from June to September;

plants may flower only once every two years. The fruits mature mostly from June to December. Plants have been seen replacing their leaves over a short span of time in the late dry season.

Probably the most variable Zanthoxylum on the island, especially in terms of leaf shape. Some BCI plants have consistently much smaller leaflets than others, and addi- tional morphological and phenological study may show them to be distinct species. Plants of the small-leaved form generally flower and fruit ahead of those with larger leaves, although the seasons overlap. This is further evidence that two taxa may be involved in what is being called Z. panamense. The small-leaved plant corresponds with the type.

This species and Z. setulosum are different from Z.

procerum in their manner of dehiscence. The fruits of

Fig. 296. Zanthoxylum belizense

Fig. 297. Zanthoxylum panamense

A S

Fig. 298. Zanthoxylum procerum ."«",'•'».-;€:«. '.•¥". -Am

Fig. 299. Zanthoxylum setulosum

Z. procerum expel their seeds from the follicle by the elastic movements of the inner wall of the carpel, whereas Z. panamense is thought to be bird dispersed because of the shiny black seeds displayed outside the valves on a slender fiber.

The prickles on the trunk may be hollow and are often inhabited by ants.

Costa Rica and Panama. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Colon, Chiriqui, Panama, and Darien.

See Fig. 297.

Zanthoxylum procerum Donn. Sm., Bot. Gaz. (Craw- fordsville) 23:4. 1897

Alcabii, Ikor, Lagarto

Dioecious tree, 8-17(20) m tall; trunk to 18 cm dbh, armed, the prickles corky, conical, with the sharp apex usually slightly off-center, the sides with weak vertical grooves; branches sparsely armed with short prickles;

outer bark with lenticels arranged in irregular vertical streaks; inner bark tan; twigs soon glabrous. Leaves alternate, imparipinnate or paripinnate, 12-45 cm long (to 60 cm on juveniles), glabrous; petioles 1-10(14) cm long, the pulvinus moderately small to much expanded; rachis canaliculate above, especially beneath insertion of each leaflet; petiolules 3-7 mm long; leaflets (2)4-18, unarmed, mostly opposite, sometimes alternate especially basally, broadest in middle, narrowed gradually to either end, gradually acuminate at apex, cuneate to attenuate with both sides ± equally decurrent at base, 4.5-14.5 cm long, 1.5-5 cm wide (to 25 cm long and 8 cm wide on juveniles), the margins usually minutely crenate and conspicuously pellucid-punctate, the surfaces ± shiny and glabrous, with numerous, minute, lepidote scales on both surfaces, lacking pellucid dots except near margin, often somewhat viscid when dried. Panicles terminal, 10-20 cm long, the branches many, sparsely puberulent, densely lenticellate and punctate, with markedly con- stricted articulations at the base at maturity; flowers unisexual, with sweet aroma, ca 2 mm long, 3-parted; calyx lobes triangular; petals broadly oblong, rounded at apex;

staminate flowers with the stamens 5, well exserted, 2-3 mm long, the pistillode minute, conical, the style short;

pistillate flowers unknown. Fruits of 1 brown follicle, 3-3.3 mm diam, globose, densely covered with lenticels and minute glandular projections, on a short stalk ca 7 mm long, the valves 2, persistent, translucent, hydroscopic, dehiscing at maturity, folding together laterally to expel seed; seed 1, rounded, ca 3 mm diam, black with brown reticulations. Croat 11670,12189.

Frequent in the forest. Flowers from February to May (sometimes from January). The fruits mature from June to November, mostly in August and September. Allen (1956) reported this species to flower in August and Sep- tember in the Golfo Dulce area of Costa Rica, although he was possibly dealing with a different species.

Distinguished by the small, glabrous leaves, which are acute at the base, and the three-parted flower. Cut parts of the plant have a very strong odor similar to that of the

67.

RUTACEAE/ZANTHOXYLUM

493

citron fruit, and the flowers have a sweet odor. The valves of the fruit are capable of expanding and contracting repeatedly during alternate periods of high and low humidity.

Southern Mexico to Panama. In Panama, known from tropical moist forest in the Canal Zone, Panama, and Darien and from premontane wet forest in Chiriqui (Progreso) and Panama (Cerro Campana). Reported from tropical wet forest in Costa Rica (Holdridge et al., 1971).

See Fig. 298.

Zanthoxylum setulosum P. Wils., Contr. U.S. Natl.

Herb. 20:480. 1922

Prickly yellow, Arcabii, Acabii, Alcabii, Tachuelo Dioecious tree, (3)6-12(20) m tall; trunk 10-15(20) cm dbh, armed, the prickles many, large, corky, oval or rounded in basal outline, the apex rounded with a sharp point set somewhat off-center; outer bark ± smooth, light brown, with many raised lenticels; inner bark tan;

wood pale yellow, the cambial layer fluted. Leaves alternate, pinnate, 15-50 cm long, conspicuously pubescent (particularly below), the trichomes erect, simple; petioles terete; rachis margined above, sometimes bearing small prickles; leaflets 15-27, subopposite, ± sessile, ovate to oblong or oblong-elliptic, acuminate, acute to rounded at base, usually inequilateral at base, 2.5-10(15) cm long, 1.5-3.5 cm wide, entire or crenulate, obscurely pellucid- punctate, sometimes glabrate in age above, rarely with a few prickles on midrib below. Panicles terminal or upper- axillary, ± congested, to 21 cm long, the branches short, sparsely puberulent; pedicels 2-3.7 mm long, glabrous or crisp-pubescent; flowers unisexual, 5-parted, 2.7 mm long; calyx ca 1 mm long, usually glabrous, rounded at apex; petals elliptic, boat-shaped, spreading, white to greenish-white, the veins prominent, 2-2.3 mm long, rounded at apex, glabrous or inconspicuously pubescent inside; stamens of staminate flowers 5, included or exserted and spreading, 1.7-2.7 mm long, the anthers about as long as or much shorter than filaments, the pistillode small, 1-4-lobed, the styles 1-4; pistillate flowers not seen. Fruits of (2)4(5) follicles, tan or brown, glabrous, the valves persistent, muricate, the inner valve whitish, curling from the base to force seed from follicle; seeds 1 per follicle, ± globose or ovoid, black, shiny, 2.5-3.3 mm long, suspended on a strong slender fiber. Croat 5430.

Frequent in the forest. Flowers in the late dry season (March and April). The fruits develop soon but may persist for a long time, maturing from April to October (sometimes to December). Leaves are shed in the dry season, and the trees may be bare for more than a month.

Ants may inhabit old spines and hollow parts of some stems.

Panama and possibly Costa Rica. In Panama, known principally from tropical moist forest on the Pacific slope in the Canal Zone, Panama, and Darien; known also from tropical dry forest in Los Santos, from premontane moist forest in Code (La Pintada), and from premontane wet forest on Code (El Cope).

See Fig. 299 and fig. on p. 20.

Dalam dokumen 35. ORCHIDACEAE/SCAPHYGLOTTIS 301 (Halaman 189-194)