Mandevilla

Shrubs, subshrubs, or suffrutescent perennials [woody vines]; latex milky. Stems erect [trailing], unarmed, eglandular-pubescent or glabrate [glabrous]. Leaves deciduous [persistent], opposite, subopposite, or occasionally subverticillate [whorled], petiolate; stipular colleters interpetiolar [absent]; laminar colleters present. Inflorescences axillary, terminal, or subterminal, cymose, pedunculate or not. Flowers: calycine colleters present; corolla yellow or white, often tinged with pink or red [pink, red, crimson, magenta, often with yellow eye], salverform, aestivation dextrorse; corolline corona absent; androecium and gynoecium not united into a gynostegium; stamens inserted at top of corolla tube; anthers connivent, adherent to stigma, connectives enlarged, truncate or 2-lobed, locules 4; pollen free, not massed into pollinia, translators absent; nectaries 2–5, distinct [connate and forming disc]. Fruits follicles, usually paired, erect or deflexed, brown to reddish brown, slender, terete or moniliform, surface smooth or striate, pubescent or glabrate [glabrous]. Seeds linear, flattened, not winged, not beaked, comose, not arillate. x = 8, 10.

Distribution

sw United States, Mexico, West Indies, Central America, South America.

Discussion

Species ca. 170 (5 in the flora).

Mandevilla is one of the largest genera of Apocynaceae, although until recently its generic delimitation has been somewhat controversial. As noted by A. O. Simões et al. (2006), the combination of great morphological diversity and wide geographic distribution has presented challenges to workers that have been reflected in the taxonomic history of the group.

The most widely accepted circumscription of Mandevilla was established by R. E. Woodson Jr. (1933), who treated the genus as comprising approximately 110 neotropical species divided into two subgenera, Exothostemon (G. Don) Woodson and Mandevilla, the latter comprising five sections. M. Pichon (1948) provided a revised treatment in which he recognized the subgenera of Woodson but proposed a new classification within subg. Mandevilla, recognizing four sections. Pichon also included Macrosiphonia in Mandevilla, arguing that the characters used by Woodson to separate these genera were arbitrary.

Until recently, few studies have examined relationships between Mandevilla and putatively related genera. J. L. Zarucchi (1991) described the monotypic genus Quiotania from northern Colombia, indicating that he felt it to be close to Mandevilla but commenting that it was not clear whether it was most closely related to Macrosiphonia, Mandevilla, or other neotropical genera such as Allomarkgrafia Woodson, Mesechites Müller Arg., or Tintinnabularia Woodson. J. Henrickson (1996b) elevated Macrosiphonia subg. Telosiphonia to generic status, noting that all of these genera (Allomarkgrafia, Macrosiphonia, Mandevilla, Mesechites, Quiotania, and Telosiphonia) formed a distinctive and closely related group. However, in a subsequent revision of the Mexican and Central American species of Mandevilla, J. F. Morales (1998) chose to main­tain a strict delimitation of the genus, following the circumscription by R. E. Woodson Jr. (1933).

Recent phylogenetic analyses based on a combination of molecular and morphological characters (A. O. Simões et al. 2004, 2006) have demonstrated that Mandevilla as circumscribed by M. Pichon (1948) is monophyletic while the genus as delimited by R. E. Woodson Jr. (1933) is paraphyletic. Macrosiphonia and Telosiphonia (as well as Quiotania) are nested within Mandevilla and are here included in the genus.

Flowering in the species of Mandevilla from the flora area is sporadic and typically follows rains from May through September.

Several non-native species of Mandevilla, especially the South American M. sanderi (Hemsley) Woodson, are often cultivated as ornamentals in the southern United States.

Selected References

None.

Lower Taxa

Mandevilla brachysiphon, Mandevilla foliosa, Mandevilla hypoleuca, Mandevilla lanuginosa, Mandevilla macrosiphon

Key

1	Flowers 3+ per inflorescence; corolla yellow.	Mandevilla foliosa
1	Flowers solitary or 2 or 3 per inflorescence; corolla white but often ferruginous upon drying.	> 2
2	Corolla tube 1–3.5 cm, shorter than to 1.5 times as long as expanded corolla throat.	> 3
3	Leaf blades ovate-lanceolate to oblong-ovate, green abaxially and adaxially; peduncles absent or to 1(–3) mm.	Mandevilla brachysiphon
3	Leaf blades linear to oblong-elliptic or oblong-ovate, white-pubescent abaxially, green adaxially; peduncles (5–)12–22(–36) mm.	Mandevilla hypoleuca
2	Corolla tube 4–10 cm, at least 2 times as long as expanded corolla throat.	> 4
4	Shrubs; rhizomes absent; petioles mostly shorter than 3 mm.	Mandevilla lanuginosa
4	Suffrutescent perennials; rhizomes present; petioles mostly longer than 3 mm.	Mandevilla macrosiphon