Ballota nigra 寬萼蘇、黑夏至草、黑苦薄荷

Common name: Black Horehound
Scientific name: Ballota nigra 寬萼蘇、黑夏至草、黑苦薄荷
Genus: Ballota 寬萼蘇屬
Family: Lamiaceae or Labiatae 唇形科, mint or deadnettle or sage family

Remarks: 

Origin: Archaeophyte (established before 1500 AD). It has a European Southern-temperate distribution. Archaeological evidence suggests that it is an ancient introduction, having been associated with human settlements since the Iron Age. 

Date:  28th July

555 An erect, branched, pubescent perennial, can reach up to 100cm, with unpleasant smell.

546

551_2 Stem with down folded hairs. (left side of the photo above is pointing downwards)

546_1 Leaf stalked (see the small leaves above), leaf oval-lanceolate to heart-shaped, blade 2-5cm, with crenate or dentate margin. Upper surface of leaf wrinkled.

553 Opposite leaves. Underside of the leaf pubescent (both sides of leaves are pubescent) and also showing the leaf stalk (1-3cm). Note the hairy and square stem.

554 Flowers in many-flowered inflorescence with numerous whorls.

545_1 Flowers are organized in verticillasters (輪狀聚傘花序), subspherical to about one-sided, with 15 to 30 flowers. Each verticillaster consist of two condensed dichasial cymes (二岐聚傘花序) at axils of normal leaves. Note the brown calyx funnel-shaped, with 5 broad, more or less equal teeth.

550 The flower bud. Note the inflorescence (described in the above photo already).

550_1 The funnel-shaped calyx and the 5 filiform (絲狀的) bracts (Bt) below. Note the square stem (it is cut by some animals? in the above photo) 

551

551_1 There are 5 filiform bracts of each flower.

547

548

547_3 Flower bud. Note the brown calyx funnel-shaped, with 5 broad, more or less equal teeth.

547_2 Corolla reddish manuve.

547_1 Flower with 2 lips. The upper one is slightly concave, like a hood, and hairy externally. The lower one is glabrous, with 2 minor lateral lobes and a major central bifid lobe.

548_1 4 didynamous (二強雄蕊的) stamens, with glabrous filaments (Ft) and yellow anthers (Ar) (it is not yellow at the stage in above photo) One style (Se) with a 2-parted stigma (Sa).