Mastixia

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Mastixia

Description

Unarmed, resinous, evergreen trees up to 40(-60) m; Leaves simple, exstipulate, entire, acute, alternate or (sub)opposite to decussate, sometimes with domatia. Flowers bisexual, greenish to yellowish. Petals valvate, 4-5(-6), thick, ovate to oblong-elliptic, inflexed at apex and 2-dentate or fimbriate, sometimes with a median ridge inside, spreading or reflexed. Stamens 4-5(-6), or 8, alternating with the petals, erect in bud; Ovary inferior, turbinate, 1-celled, surmounted by a prominent, fleshy, persistent disk c. ⅓ the height of the receptacle; Ovule 1, pendulous laterally from the roof of the cell. Seed fitting the fruit cavity;

Distribution

Asia-Temperate:, Hainan (Hainan present) Asia-Tropical:, East Himalaya (Bhutan present); Thailand (Thailand present) Burma: present Ceylon: present NE. India: present New Britain: present S. Yunnan: present SE. Asia: present Solomon Islands: present Western Ghats: present
About 13 spp. in SE. Asia (Western Ghats&Ceylon, NE. India, Bhutan, Burma, Thailand, Indo-China, S. Yunnan, Hainan) through Malesia to New Britain and the Solomon Islands. .

Anatomy

For general anatomical surveys also giving the older literature see .
.

The wood of Mastixia like that of most other Cornaceae is primitive. It has diffuse, exclusively solitary vessels with scalariform perforations (many-barred), fibre-tracheids, diffuse parenchyma, and heterogeneous rays. MOLL & JANSSONIUS l.c. reported vertical intercellular canals in Mastixia rostrata and M. trichotoma. The latter are absent from M. tetrapetala studied in Leiden. The leaf and twig anatomy of Mastixia is characterized by the occurrence of secretory canals. This important feature is absent from the other genera of the Cornaceae. Their presence in Mastixia can be used as an argument to stress the affinities of Cornaceae with Araliaceae and Umbelliferae of the Cornales for which families they are typical. — P. BAAS.

Taxonomy

Mastixia was subdivided into two subgenera by WANGERIN (1910) on the 4- and 5-merousness of the flowers respectively. Though this character is still used for discrimination of species, it seems artificial for subgeneric rank. Instead, I have proposed another subdivision (1976) into two subgenera, in one of which (subg. Manglesia) the stamens number 8 and are arranged into 2 whorls, while in subg. Mastixia the stamens number 4-5(-6) and stand in 1 whorl. Other differential characters support this subdivision; see also the key.

Uses

Although trees may reach a considerable size, the scattered occurrence does not contribute to general use as timber; besides, the timber is not of good quality and is only used for minor purposes. Cf. .

Notes

In key and descriptions the width of the submature flower is that of the corolla.
About the use of the term 'merousness' of the flower it should be remarked that this cannot be used in the strict sense, as 4- and 5-merous flowers often occur in one inflorescence. If it is said 'basically 4-merous', this means that at least 80 % of the flowers are 4-merous and the same holds for basically 5-merous flowers, so that the prevalent pattern is obvious.
Moreover it should be remarked that the number of sepals frequently tends to be higher than that of petals and stamens.
In exceptional cases identification of sterile or immature material must remain uncertain.
Unfortunately no separate key can be provided for fruiting material.

Citation

HARMS - in E. & P., Nat. Pfl. Fam. 3. 1898: 262
DANSER - in Blumea. 1934: 47
HALL.f. - in Beih. Bot. Centralbl. 1916: 40
WANGERIN - in Pfl. Reich Heft. 1910: 19
MATTHEW - in Blumea. 1976: f. 1-6