Citrus

Family Rutaceae. Order Sapindales.

Large trees to small trees. Buttresses absent. Spines present, or absent; on trunk, or on branches. Stilt roots absent. Bark gray, brown; not peeling in strips. Vertical stripes in the inner bark or wood absent. Odor absent. Exudate absent. Terminal buds not enclosed by leaves.

Complex hairs absent. Stinging hairs absent. Mature twig indumentum absent.

Leaves spiral; not scale-like; simple; all of the same type; not modified into spines; coriaceous, or leathery; gland-dotted; symmetric at the base; dissected, or not dissected; pinnately lobed; smooth margined, or wavy margined, or with small to large teeth on margin. Epidermis waxy, or not waxy. Venation pinnate. Secondary veins open; prominent, or not prominent, but visible. Smallest veins not prominent, but visible, or not visible; net like. Intramarginal vein present, or absent. Stalk of blade less than a quarter the length of the blade; winged, or not winged; attached to base of leaf blade; not swollen, or swollen; swollen at one end. Stipules absent. Domatia absent. Basal glands absent. Hairs on mature leaf present, or absent; dense, or sparse.

Inflorescences present, or represented by solitary flowers only; axillary; the flowers from a single point on the stem, or on an unbranched axis, or on a branched axis; specialized inflorescence units present, or absent; specialized inflorescence units corymbs; numerous and persistent inflorescence bracts absent. Flowers bisexual, or at least some flowers unisexual; with male and female flowers on the same plant; stalked; about 0.5 cm long or across; round; with male or female parts not raised on a column. Hypanthium absent. Disk present; the stamens outside the disk. Perianth present; with distinct calyx and corolla whorls. Sepals 4-5; free, or partially joined; persistent in fruit; not growing any further after flowering. Epicalyx absent. Petals present; (4-)5(-8); free; fleshy, or not fleshy; deciduous; not stalked; entire. Stamens 100 (many); filaments present; joined, or free of each other; free of the perianth; all equal in size; polystemonous. Anthers 2 loculed; attached along the side; not awned; dehiscing by long slits. Ovary inferior. Carpels joined; (6-)8(-18). Locules (6-)8(-18). Styles solitary. Stigmas 1 lobed; distinctive; head shaped. Fruit berry-like (hesperidium); fleshy; not multiple; not splitting; not enclosed in, or sitting on, fleshy perianth parts; wingless. Seeds 10-100 per fruit (many); less than 5 mm; wingless; uniform in cross-section; aril absent; endospermic.

Spines, when present, single; twigs angled when young, round when older; petioles usually winged. Taxon images: citrus.gif


Cite this publication as: Jarvie, J.K. and Ermayanti (1996 onwards). `Tree Genera of Borneo - Descriptions and Illustrations' URL http://django.harvard.edu/users/jjarvie/Borneo.htm/.
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.