亜種[ashu] subspecies
異機種[ikishu] heterogenous equipment
異種[ishu] different kind (species, variety)
育種[ikushu] (plant) breeding
育種家[ikushuka] (plant) breeder

育種所[ikushujo] (plant) nursery
一種[isshu] species
一粒種[hitotsubudane] an only child
種違い[tanechigai] half-brother
艶種[tsuyadane] love affair

草臥れる[kutabireru] to get tired
遺草[isou] posthumous works
一年草[ichinensou] annual (plant)
詠草[eisou] draft poem
下草[shitakusa] undergrowth

仮名草紙[kanazoushi] story in the kana
伽草子[togizoushi] fairy-tale book
海草[kaisou] marine plant
乾草[kansou] hay
甘草[kanzou] liquorice

悪質[akushitsu] bad quality
悪質化[akushitsuka] worsening
異質[ishitsu] different (quality, nature)
音楽の素質[ongakunososhitsu] aptitude for music
音質[onshitsu] tone quality

可塑物質[kasobusshitsu] plastics
画質[gashitsu] image quality (film, video, etc.)
灰白質[kaihakushitsu] gray matter
企業体質[kigyoutaishitsu] financial content
器質的[kishitsuteki] organic