''Mitrephora keithii '' is a species of plant in the family Annonaceae. It is native to

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

, Peninsular Malaysia and Thailand. Henry Nicholas Ridley, the English botanist who first formally described the species, named it in honor of Dr. A. Keith who collected the sample that Ridley examined.

Description

It is a small tree reaching 6 meters in height. Its leathery, oval to lance-shaped leaves are 7.5-17.5 by 2.5-5 centimeters with pointed bases tips. The upper side of the leaves are matt and hairless, while the undersides are covered in sparse, fine hairs. The leaves have 7-11 pairs of secondary veins emanating from their midribs. Its petioles are 3–8.5 by 1.5-3 millimeters and covered in sparse, fine hairs. The flowers occur in groups of 3 or fewer on a rachis. Flowers are attached to the rachis by fleshy, densely hairy pedicels that are 4.5-9 by 0.8-1.5 millimeters. The pedicels have an oval, basal bract that is 1.5 by 2 millimeters, and another upper bract that is 1–2.5 by 1.5-2.5 millimeters. Its flowers have 3 triangular sepals that are 3-4 by 3–4.5 millimeters. The sepals are covered in dense, brown hairs on their outer surface and sparse hairs on their inner surface. Its 6 petals are arranged in two rows of 3. The yellow, oval, outer petals are 9-18 by 6.5-9.5 millimeters and come to a point at their tips. The outer surface of the outer petals is covered in dense, brown, fine hairs while the inner surface is sparsely hairy. The edges of the outer petals are slightly wavy when mature. The inner petals are yellow with pink edges. The inner petals are 7.5-10 by 4.5-6 millimeters. The inner petals have dense, fine hairs on their outer surface. The inner surface of inner petals is covered in hairs that become longer at the tip. Its flowers have

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

that are 1-1.2 by 0.5-0.8 millimeters. Its flowers have 12-14

carpels Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

that are 1.5-1.8 by 0.5-0.8 millimeters. The carpels have 6-12 ovules. Its fruit occur in clusters of 4–6 on pedicels that are 10 by 2 millimeters and covered in sparse, fine hairs. The smooth, sparsely hairy, oblong fruit are 14-30 by 7.5 millimeters. The fruit are attached to the pedicel by stipes that are 3-3.5 by 2 millimeters and covered in sparse, grey-brown, fine hairs. Each fruit has 4-12 seeds that are 8.5-14 by 7.5 millimeters.

Reproductive biology

The pollen of ''M. keithii '' is shed as permanent tetrads.

Habitat and distribution

It has been observed growing in evergreen forests with limestone soil at elevations of 0 to 300 meters.

References

{{Taxonbar, from=Q17139971 keithii Flora of Myanmar Flora of Peninsular Malaysia Flora of Thailand Plants described in 1911 Taxa named by Henry Nicholas Ridley