Valmiki Ramayana Sundara Kanda Sarga 15 Shloka 10

तत्र there, सहस्रशः thousands, अशोकाः Ashoka, केचित् some, शातकुम्भनिभाः shone like gold, केचित् some, अग्निशिखोपमाः like the flames of fire, केचित् some, नीलाञ्जनिभाः like the black collyrium.

There were thousands of ashoka trees some of which shone like gold, others like the flames of fire and some dark as collyrium.