Question

Which of the following genera belong to warm orchids?
(A) Cymbidium
(B) Phalaenopsis
(C) Miltonia
(D) Dendrobium
Choose the correct answer from the options given below:

• A. (A) and (B) only.
• B. (A), (C) and (D) only.
• C. (B) and (C) only.
• D. (B) and (D) only.

Hint:

Orchids have different temperature needs:
Phalaenopsis (Moth Orchids) are typically warm growers.
Dendrobium is diverse, but includes many important warm-growing types.
Cymbidium generally prefers cooler to intermediate conditions.
Miltonia can be intermediate to warm (true Miltonias) or cool (Miltoniopsis).

Answer 1

The Correct Option is D

Orchids are often categorized by their temperature preferences for optimal growth: cool-growing, intermediate-growing, and warm-growing.
(A) Cymbidium: Most Cymbidium species and their hybrids are considered cool to intermediate growers. They often require a significant drop in temperature to initiate flowering.
(B) Phalaenopsis (Moth Orchids): These are generally warm-growing orchids, preferring temperatures typically found in tropical lowlands (e.g., night temperatures not below 16-18°C, day temperatures 24-29°C).
(C) Miltonia (Pansy Orchids): This genus is split by some into Miltonia (warmer growing, Brazilian types) and Miltoniopsis (cooler growing, "pansy orchids" from higher altitudes). If referring to true Miltonia, they can be intermediate to warm. However, they are not as consistently "warm" as Phalaenopsis across the board.
(D) Dendrobium: This is a very large and diverse genus with species adapted to a wide range of climates. It includes many warm-growing species (e.g., those in the Phalaenanthe and Spatulata sections, often called "Phalaenopsis-type Dendrobiums" or "Antelope Dendrobiums"), as well as intermediate and cool-growing species. Considering the options: Option (4) suggests (B) Phalaenopsis and (D) Dendrobium.
Phalaenopsis (B) is definitely a warm-growing genus.
Dendrobium (D) contains many popular warm-growing species and hybrids, making it appropriate to include in a list of "warm orchids" even if the entire genus isn't exclusively warm. This combination is plausible as both genera have significant representation in the warm-growing category. Cymbidium (A) is mostly not warm. Miltonia (C) is mixed but not as clearly "warm" as Phalaenopsis. (B) and (D) only.