Thursday, 26 May 2022

Hottonia palustris 水堇, 水堇菜, 水紫羅蘭, 帕鹿雪花, 美洲赫頓草

Common name: Water-violet
Scientific name: Hottonia palustris 水堇, 水堇菜, 水紫羅蘭,  帕鹿雪花, 美洲赫頓草Genus: Hottonia 雪花草屬
Family: Primulaceae 報春花科, primrose family

Remarks*:

Origin: native

Date: 19th May

This population of water-violets are found in an old marl 泥灰 pit (a pit from which a mixture of clay and carbonate of lime is excavated to use as a fertilizer.)  in a nature reserve. They are flowering in a semi-shaded woodland.


A floating and rooting aquatic perennial.

Flowering stalk emerged from the water.


Photo enlarged below to see the arrangement of the leaves.



Clusters of leaves are radiated from the centre where the flowering stalk appears.

Photo enlarged below.

A rosette of leaves and the submerged stem.

The pinnate leaves are overlapping each other forming a mat.

Leaves are submerged, whorled. They are pinnate with narrow lobes.


Photo enlarged below to see the arrangement of leaves.


A rosette of leaves.


Pinnate leaves with narrow lobes.



Flowers are whorled. They are flowering from the bottom of the inflorescence. Those at the bottom of it had the petals withered and dropped already. Those in the middle are flowering whereas there are flowering buds at the top. 


Photo enlarged below to see the flower buds.


The flowering buds and the bracteoles.



The flowering buds are ready to bloom.



Side view of the flower showing the sepals and bracteole (the narrow green leaf-like structure at the base of each individual flower).


The underside of the petals and the sepals.

Another angle and another flower.



The underside of the anthers.

Photo enlarged below to see the details of the flower.


Flower is 20-25 mm across. 5 lilac petals with yellow-throat.


This plant is heterostylous 花柱異長的 (two forms of flowers exist in the population). The flower in the above photo is a short-styled flower (the thrum flower), the stamens are long but the pistil is short.

Another flower, enlarged below.

This flower has paler petals. Maybe it is an older flower with the lilac color is fading.

Another flower, enlarged below.


A more lovely colored flower.

Another flower, enlarged below.



5 protruding stamens and 1 short stigma in this thrum flower (short-styled flower).

The withered flowers at the bottom of the inflorescence. Photo enlarged below to see the details.


Petals had already dropped, only some sepals and the pistil are left. It is said that fruiting could only be developed after fertilization occurs between the pin and thrum flowers.


Moehringia trinervia 三脈種阜草

Common name: Three-nerved Sandwort
Scientific name: Moehringia trinervia 三脈種阜草
Genus: Moehringia 種阜草屬
Family: Caryophyllaceae 石竹科, pink or carnation family

Remarks*:

Origin: native

Date: 19th May


A slender, branched, prostrate to ascending pubescent annual.


Leaves in opposite pairs. Leaves pointed ovate (not linear), 6-25 mm, conspicuously 3-veined. Stipules absent.


Hairs on the stem.


Underside of the leaves. 3-veined is clearly seen.

Flower about 6 mm in diameter.

Photo enlarged below to see the details of the underside of the flower.


Underside of the flower showing the sepals. Sepals are free, transparent at the edges.

Photo enlarged below to see the details of the flower.


5 sepals, 5 petals, 10 stamens, 3 styles. Green ovary. Petals are shorter than sepals. Petals are entire, not divided.

Another flower, enlarged below to see the details.

5 sepals, 5 petals, 10 stamens, 3 styles.