Piper nigrum

Piper nigrum (2n=52,78,104...) commonly known as black pepper is cultivated for its fruit, which is used as a spice and seasoning in the dried form. It is also used in traditional medicine.

Piper nigrum spike on the vine.

Scientific classification

Kingdom: Plantae

Subkingdom: Tracheobionta

Superphylum: Spermatophyta

Phylum: Magnoliophyta

Class: Magnoliopsida

Order: Piperales

Family: Piperaceae

Genus: Piper

Species: P. nigrum

Inflorescence

The inflorescence is a pendulous spike or catkin that emerges from the stem node opposite to the leaves. 

Anthesis

Foliage, Flowers and Fruit of the Pepper Plant.

Anthesis occurs in the evening. The flowers open from the base of spike to the tip (acropetal). Pepper is protogynous, i.e., the gynoecium develops before androecium. So generally flowers lower on the spike are pollinated by pollen dehising from those situated above. So the pollination is by geitonogamy (by means of gravity).

Floral Morphology

Wild pepper is dioecious but cultivated varieties are bisexual, and thus more productive. Whitish to yellow-green small sessile flowers are arranged spirally along the spike. Flowers are bracteolate, with four peltate bracts.

Perianth: The flowers are apetalous, infact lack the entire perianth.

Androecium: The androecium is composed of 2-4 stamens on either side of the ovary. The short filaments bear oval shaped anthers with two pollen sacs.

Gynoecium: Gynoecium is composed of a single (or 3-5) carpel(s). At the center of the flower is the  unilocular superior ovary. The style is short with white star shaped stigma. The stigma is covered with a viscous liquid that favour fertilization.

Fruit

Fruits are round, berry-like, up to 6 mm in diameter, green at first but turning red as they ripen, each containing a single seed. The fruit is botanically a drupe and when dried is called peppercorn. 

Green drupes on spike and white (dried ripe) & black (dried unripe) peppercorns

Arbitrary Numbers
The spikes are usually 7-35cm long and bear 70-100 flowers. 50–60 fruits are borne on each spike. Anthesis lasts about 7-8 days.

Useful Links: 

1. Floral diagram and formula of family Piperaceae
2. Kew Botanical Garden Record

Vanilla planifolia

Vanilla planifolia (2n=32) is a species of vanilla orchid and is one of the primary sources for vanilla flavouring, due to its high vanillin content. 

Vanilla planifolia inflorescence on the vine

Scientific classification

Kingdom: Plantae

Phylum: Angiosperms

Class: Monocots

Order: Asparagales

Family: Orchidaceae

Subfamily: Vanilloideae

Genus: Vanilla

Species: V. planifolia

Vanilla planifolia 1887 illustration from Köhler's Medicinal Plants

Inflorescence
Inflorescence emerge as a light green protuberance from the leaf axil. It is a 5-8 cm long generally un-branched (rarely branched) raceme. 

Anthesis

Anthesis is in the early morning. Flowers open acropetaly i.e., from the base of the inflorescence upwards. Each inflorescence has only a single flower open at any one time and a flower lasts only one day.

Floral Morphology

Longitudinal section of Vanilla flower showing Pollinia and Rostellum

Vanilla bears large zygomorphic bisexual flowers that are pale geen or cream or yellow in colour. Flowers are pedicellate, borne on a short pedicel and bracteolate, each flower is subtended by a small pointed bract. flower is turned upside down   (resupinate) as it develops so the labellum is on the bottom.

Perianth: 3 narrow pointed oblong sepals constitute the calyx. Corolla consist of 2 upper petals that resemble the sepals but are slightly smaller, and a trumpet shaped labellum or lip.

Androecium:  A single pollinia is attached to labellum, bearing at its tip 2 pollen masses covered by a cap/hood. 

Dried Vanilla pods with seeds inside

Gynoecium: Concave stigma is  situated below the pollinia is separated from it by a thin flap-like membrane or rostellum, which prevents natural pollination.  Style fused with the filaments of the stamen form the column or gynostemium. Ovary is inferior and long. 

Fruit

Fruit a pendulous, narrowly cylindrical capsule, obscurely 3-angled, splitting longitudinally when ripe. Seeds numerous, globose, non-endospermous, black.

Arbitrary Numbers
On a single wine 7-15 inflorescence emerge in a season. Each inflorescence carries 15-25 large flowers. It takes 50-60 days from floral initiation to anthesis. Flowering period extends 14-30 days. 

Useful Link:Floral formula and floral diagram of Orchidaceae family