The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

butterfly-pea, pigeonwings

Asian pigeonwings, blue pea

Habit Subshrubs [lianas, trees], unarmed; rhizomes (xylopodia) woody, subterranean, erect or horizontal, with slender, distal portion tapering deeply underground.
Stems

erect or distally lax and twining or trailing [scandent], uncinate-pubescent.

1–6 from crown, trailing and intertwining to form tangled mats or climbing, terete, weakly striate, 500 cm;

internodes ± straight to weakly flexuous, distal internodes nodding;

branches mostly proximal, sometimes distal.

Leaves

alternate, odd-pinnate;

stipules present, persistent, striate;

petiolate;

leaflets 3–7, stipels striate, blade margins entire, surfaces glabrous or pubescent.

stipules linear, 4–10 × 0.5–1 mm, apex acuminate;

petiole subangular, canaliculate adaxially, 1–4 cm;

stipels linear, 1–3 mm;

petiolules 1–3 mm;

rachis canaliculate adaxially, 2–7 cm;

leaflets 5 or 7, blades polymorphic, ovate, elliptic, obovate- or ovate-elliptic, or oblong, 10–50(–70) × (4–)10–30 mm, membranous, base cuneate to rounded, primary lateral veins 5 or 6 pairs, apex acute to obtuse or retuse, surfaces glabrate.

Inflorescences

1 or 2(–4)-flowered, axillary, pseudoracemes, erect to lax, flowers chasmogamous, sometimes also cleistogamous;

bracts present, persistent;

bracteoles persistent or tardily deciduous, appressed to calyx, rarely enlarged and obscuring calyx.

1(or 2)-flowered, 0.5–1 cm, flowers chasmogamous;

bracts ovate to lanceolate, 2–4(–5) × 1 mm.

Peduncles

0.3–1.5 cm.

Pedicels

paired, borne laterally at apex, spirally twisted to invert flowers.

3–6 mm;

bracteoles deciduous by fructification, broadly ovate to suborbiculate, conspicuous, shorter than calyx tube or subequaling and obscuring calyx, (4–)6–11(–15) × (4–)6–11(–15) mm, apex acute to rounded, apiculate, glabrous.

Flowers

usually papilionaceous, actinomorphic in C. ternatea var. pleniflora; chasmogamous flowers resupinate, rarely all petals subequal, bannerlike, 35–60 mm; cleistogamous flowers apetalous, banner rarely hidden within calyx, reduced, inconspicuous except in fruit;

calyx persistent, funnelform, lobes 5, adaxial 2 subconnate, 4 wider, often shorter than abaxial lobe, shorter than tube;

corolla lilac, blue, purplish, or blue-violaceous, sometimes with white to yellow medial strip [white with purplish venation on banner];

banner conduplicate, short-clawed, spurless, obovate-orbiculate, 40–60 mm, much larger than other petals, arising from lower side of resupinate flower, emarginate;

wings slightly adherent to keel, long-clawed, falcate-oblong or spatulate, shorter than banner and extending beyond keel, base without auricles;

keel incurved, long-clawed;

stamens 10, diadelphous, usually distinct apically, rarely ± distinct and some in bundles;

anthers dorsifixed;

ovary stipitate;

style elongated, flattened, base persistent as beak in fruit, apex dilated and geniculate distally, bearded lengthwise.

Fruits

legumes, stipitate to subsessile, straight to subfalcate, convex and depressed between seeds or flat, linear, 6–11 mm wide, dehiscent by valves breaking from replum, spirally twisting to expel seeds, leathery, margins thickened, apex beaked, uncinate-pubescent.

Legumes

yellowish green to green becoming light brownish to tan, flat, (50–)70–110 × 8–11 mm;

stipe 1–2 mm, enclosed within calyx with base of valves.

Seeds

1–10[–12], cuboidal, globose, or subreniform [reniform].

7–10, brown becoming black, subreniform, compressed, 4–5 × 5–6 mm, not viscid.

Xylopodium

proximal portion erect, cylindric, 6–15 × 0.9–1.5 cm;

distal portion 0.3+ m × 3–6 mm.

Papilionaceous

flowers: calyx tube greenish, 8–14 × 3–4 mm near base becoming 6–9(–11) mm wide, shrinking slightly in fruit;

lobes oblong, 7–12 × 3 mm, apex acute;

corolla pale blue to azure or blue-violaceous with white to yellow medial strip, or white with greenish white medial strip;

banner 40–55 mm, claw 2–4 mm;

wing blades 17–28 × 7–13 mm, claw 7–11 mm;

keel 7–10 × 4–6 mm, claw 14–18 mm;

staminal tube 16–20 mm;

filaments distinct, 3–4 mm;

anthers lanceolate, 1–1.5 mm;

ovary 6–9 mm, densely white-strigose;

style 14–17 mm, geniculate 5–8 mm from distal end.

Actinomorphic

flowers (“double”): calyx similar to papilionaceous flowers;

corolla azure to dark blue, petals bannerlike;

stamens usually diadelphous or distinct, sometimes with fused bundles of 2–5;

ovary 6–9 mm, densely white-strigose;

style 14–17 mm.

x

= 8, (12).

Clitoria

Clitoria ternatea

Distribution
from USDA
United States; Mexico; Central America; South America; West Indies; Asia; Africa; Pacific Islands; Australia
[BONAP county map]
from USDA
Africa [Introduced in North America; introduced also in West Indies, Central America, South America, Asia, Pacific Islands, Australia]
[BONAP county map]
Discussion

Species ca. 60 (3 in the flora).

Species of Clitoria are usually associated with sandy soils. Fruits and seeds are variable; floral traits are consistent.

Clitoria is divided into three subgenera and eight sections; the introduced species in the flora area belongs to subg. Clitoria, and the two native species belong to subg. Neurocarpum (Desvaux) Baker sect. Mexicana Fantz.

Cleistogamy has been reported for species of Clitoria only recently. Cleistogamous flowers are inconspicuous. In the flora area, chasmogamous flowers occur predominately from May to mid July (to September); cleistogamous flowers occur from mid July onward. Both flower forms occur on the same plant. Inflorescences with both chasmogamous and cleistogamous flowers are rare.

Clitoria and Centrosema have resupinate, papilionaceous flowers. Historically, the similarity in appearance has resulted in frequent misidentifications. Both genera have microuncinate or uncinate hairs (viewed at 20–30×) on their vegetative and reproductive structures. Suffrutescent members have aerial stems arising seasonally from a subterranean woody rhizome (xylopodium) that is seldom collected. The proximal portion of the xylopodium is thickened and scarred with nodes of prior aerial stems. Extending from this is an elongated, narrow, distal portion that extends laterally away from the aerial plant, which extends deeper into the ground, and breaks easily as one attempts to collect it. Centrosema is distinguished by campanulate calyces, U-curved styles, corollas V-shaped basally, wings subequal to keels, and fruits flat, each with a raised costa near each margin.

Some species of Clitoria are tropical agronomic crops and medicinal plants and are useful for pesticidal properties, fish poisons, and natural dyes. Some species are valued as cultivated ornamentals, including the three species treated here plus C. biflora Dalzell, C. brachystegia Bentham, C. fairchildiana R. A. Howard, C. heterophylla Lamarck, and C. laurifolia Poiret (P. R. Fantz 1991).

Nauchea Descourtilz, Ternatea Miller, and Vexillaria Eaton are illegitimate names that pertain here.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Varieties 3 (2 in the flora).

Variety angustifolia Hochstetter ex Baker f. is distinguished by having white petals and narrow leaflet blades; it is native to eastern Africa from Mozambique northward.

Clitoria ternatea is anthropogenic; it is cultivated and naturalized pantropically. The species is used medicinally for treating human ailments, as a dye, in treatment of scorpion stings and venomous snakebites, as a forage crop, and as an ornamental vine. It is cultivated in the United States outdoors as an annual or under glass as a perennial. This species is a profuse bloomer and seed producer, blooming year-round in tropical areas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Leaflets 5 or 7; petioles 1–4 cm; rachis 2–7 cm; legumes subsessile, flat, yellowish green to green becoming light brownish to tan; seeds not viscid; bracteoles broadly ovate to sub­orbiculate; cleistogamous flowers absent.
C. ternatea
1. Leaflets 3; petioles 1.5–10 cm; rachis 0.7–2(–2.5) cm; legumes stipitate, convex, brown; seeds viscid; bracteoles (of chasmogamous flowers) linear-lanceolate or lanceolate to lanceolate-ovate; cleistogamous flowers present.
→ 2
2. Calyx tubes 7–10 mm, purplish tinged near base; leaflet blades linear, linear-lanceolate to oblong-lanceolate or, sometimes, proximal ones narrowly elliptic, 5–15 mm wide, primary lateral veins 6–8 pairs; stipules 2–4 mm; stipels 1–3 mm; legume stipes 15–21 mm; cleistogamous flowers: bracteoles 2(–3) mm, calyx tube 3–4 mm, legume stipe 9–14 mm; s Florida.
C. fragrans
2. Calyx tubes 10–14 mm, greenish; leaflet blades ovate, oblong-ovate, elliptic-oblong, lanceolate, lanceolate-ovate, oblong, or elliptic, 10–40(–65) mm wide, primary lateral veins 7–12 pairs; stipules 4–8 mm; stipels 3–8 mm; legume stipes 12–17 mm; cleistogamous flowers: bracteoles 3–5 mm, calyx tube 4–5 mm, legume stipe 5–10 mm; e, se United States to e Texas, se Arizona.
C. mariana
1. Flowers papilionaceous, with 1 bannerlike petal; stamens diadelphous.
var. ternatea
1. Flowers actinomorphic, with 5 bannerlike petals; stamens distinct or connate in bundles of 2–5.
var. pleniflora
Source FNA vol. 11. Author: Paul R. Fantz. FNA vol. 11.
Parent taxa Fabaceae > subfam. Faboideae Fabaceae > subfam. Faboideae > Clitoria
Sibling taxa
C. fragrans, C. mariana
Subordinate taxa
C. fragrans, C. mariana, C. ternatea
C. ternatea var. pleniflora, C. ternatea var. ternatea
Synonyms Martiusia
Name authority Linnaeus: Sp. Pl. 2: 753. (1753): Gen. Pl. ed. 5, 334. (1754) Linnaeus: Sp. Pl. 2: 753. (1753)
Web links