Manual of the New Zealand Flora/Apocynaceæ
Order XLVIII. APOCYNACEÆ.
Erect or climbing shrubs, rarely trees or herbs, juice often milky. Leaves opposite or whorled, very rarely alternate, simple and entire; stipules wanting. Flowers regular, hermaphrodite, usually in axillary or terminal cymes. Calyx inferior, 4-lobed or -partite; lobes imbricate, often glandular at the base. Corolla gamopetalous, hypogynous, funnel- or salver-shaped; tube often hairy or scaly within; lobes 5, rarely 4, spreading, usually contorted in the bud. Stamens 5, rarely 4, inserted on the tube of the corolla; filaments short; anthers often sagittate, either free or connate and adhering to the stigma; pollen granular. Ovary superior, usually composed of 2 carpels connate only by their styles, but in one tribe the carpels are wholly combined into a 2-celled ovary with axile placentas or into a 1-celled ovary with 2 parietal placentas; ovules 2 or several or many; style single or separated at the base only, thickened above; stigma entire or 2-fid, often constricted in the middle. Fruit generally of 2 follicles opening along the inner pdge, sometimes a drupe or berry. Seeds various, often with a tuft of silky hairs; albumen generally present; embryo straight, radicle usually superior.
A large order, abundantly represented in the tropics of both hemispheres, less plentiful in extra-tropical warm regions, and decidedly rare in the temperate zones. Genera about 100; species under 1000. The order includes many poisonous plants, some (as the ordeal-tree of Madagascar, Tanghinia venenifera) being exceedingly virulent. Others are employed medicinally as drastic purgatives or febrifuges. A few species yield indiarubber, but on the whole the family is not of much economic importance. The flowers are often of considerable beauty, and many genera are cultivated in gardens or greenhouses. The single New Zealand genus extends through Australia to India and Ceylon.
1. PARSONSIA, R. Br.
Twining shrubs, with long slender branched stems, often woody below. Leaves opposite. Flowers small, in terminal or axillary corymbose cymes. Calyx 5-partite, naked or glandular within or furnished with 5 scales. Corolla salver-shaped; tube short, cylindrical or nearly globular, throat naked; lobes 5, spreading, the edges overlapping to the right. Stamens inserted about the middle of the corolla-tube or below it; filaments often twisted; anthers included or exserted, cohering in a cone or ring round the stigma, cells produced into 2 rigid empty basal lobes. Hypogynous scales 5. Ovary 2-celled; style slender; ovules numerous in each cell. Fruit elongated, cylindric, of 2 coherent follicles which ultimately more or less separate from one another. Seeds linear or oblong, numerous, with a tuft of long silky hairs at the tip.
A small genus of about 12 species, found in tropical Asia, the Malay Archipelago, Australia, and New Zealand. Both the New Zealand species are endemic.
| Flowers ¼ in. Jong. Calyx ⅓ as long as the corolla-tube. Anthers included | 1. P. heterophylla. |
| Flowers ⅛ in. long. Calyx about as long as the corolla tube. Anthers exserted | 2. P. capsularis. |
1. P. heterophylla, A. Cunn. Precur. n. 402.—A tall and slender branching climber, often ascending trees to a considerable height; stems tough and pliant, in old specimens woody towards the base; young branchlets terete, more or less pubescent. Leaves extraordinarily variable in size and shape; of young plants 1–5 in. long, narrow-linear, linear- or obiong-spathulate, or linear-oblong, entire or irregularly sinuate or provided with 2–4 rounded lobes on each side, sometimes linear and expanding at the tip into an oblong or rounded blade; of mature plants 1½–3½ in. long, usually from ovate or oblong-ovate to ovate-lanceolate or elliptic-lanceolate, sometimes obovate, more rarely narrower and lanceolate or linear, acute, petiolate, coriaceous, deep shining green above, paler beneath, veins transverse. Cymes large, many-flowered, 1½–4 in. long, terminal and axillary. Flowers white, sweet-scented, ¼ in. long. Calyx-lobes about ⅓ as long as the corolla-tube. Corolla with a long tube often inflated below the throat; lobes much shorter than the tube. Anthers included within the corolla-tube. Capsule 3–6 in. long, terete, acute.—Hook. f. Fl. Nov. Zel. i. 181. P. albiflora, Raoul, Choix, 17. Hook. f. Handb. N.Z. Fl. 187. P. variabilis, Lindl. in Journ. Hort. Soc. v. (1850) 196. P. macrocarpa, Col. in Trans. N.Z. Inst. xiv. (1882) 331.
North and South Islands: Abundant from the Three Kings Islands and the North Cape to Foveaux Strait. Sea-level to 2500 ft. Kaiku; Kaiwhiria. November–March.
I have restored Cunningham's name for this species, it having at least five years' priority over that of Raoul.
2. P. capsularis, R. Br. in Mem. Wern. Soc. i. (1809) 65.—Habit of P. heterophylla, but smaller and more slender. Leaves equally variable, of young plants ¾–3 in. long, narrow-linear or lanceolate to spathulate, entire or sinuate or irregularly lobed; of adult plants varying from extremely narrow-linear, 1–4 in. long by sometimes barely 110 in. broad, to oblong or oblong-lanceolate, 1–2½ in. long by ½–¾ in. broad, obtuse or subacute, coriaceous; margins usually entire. Cymes few or many-flowered, axillary and terminal, usually shorter than the leaves. Flowers small, ⅛ in. long. Calyx-lobes equalling the corolla-tube or very little shorter. Corolla campanulate, tube short; lobes revolute, as long as the tube. Anthers exserted.—A. D.C. in D.C. Prodr. viii. 401 (in part); Raoul, Choix, 17; Hook. f. Fl. Nov. Zel. i. 180. P. rosea, Raoul, l.c. 16; Hook. f. l.c.; Handb. N.Z. Fl. 188. P. Forsteri, G. Don. Gen. Syst. iv. 79. P. ochracea, Col. in Trans. N.Z. Inst. xxii. (1890) 480. Periploca capsularis, Forst. Prodr. n. 126; A. Rich. Fl. Nouv. Zel. 205.
North and South Islands: From the North Cape to Foveaux Strait, not uncommon. Sea-level to 2000 ft. Aka-kiore. November–March.
Easily separated from the preceding by the smaller campanulate flowers with a short tube and exserted anthers. Forster's diagnosis, and A. Eichard's description, drawn up from some of Forster's own specimens, prove beyond doubt that this species is the original Periploca capsularis. There seems to be no sufficient reason for sinking the specific name in favour of the much later one bestowed by Raoul.