星球屬多肉植物，原產墨西哥。單莖，球形至圓桶形，最大60~100cm高，直徑10~20cm，有3~7稜(通常5稜)，綠色外表有微小白色毛狀鱗片；橫切面形似海星，幼株造型有如主教帽。刺座褐色，無刺是最大特徵。花黃色，直徑4~6cm。開花期暖季。

A succulent plant of the genus Astrophytum, native to Mexico. Stem solitary, spherical to barrel-shaped, up to 60-100cm high, 10-20cm in diameter, with 3-7 ribs (usually 5). The green bark is covered with fine whitish trichome scales. Stem cross-section starfish-like, and resembling a bishop's hat when young. The areoles are brown and have no spines which is the most prominent feature. Flowers yellow, 4-6cm in diameter, blooming in warm seasons.

栽培：半日照通風環境下可生長良好，炎夏時切勿讓植株曝曬以免曬傷。為了防止爛根等情形，需採用排水透氣且微鹼性的介質，介質乾燥才澆水。生長緩慢，園藝品種通常使用嫁接方式來促進生長。

The plant thrives in partial sun and airy conditions, however, direct exposure in high summer may cause signs of scorch, such as sunburn. Use draining and breathable soil to avoid root rotting and other problems. Watering only when the soil dries. As a slow grower, grafting is often used to promote cultivars to grow.

無刺可親的仙人掌，可愛的外表吸引人收集。有各種稜數的變種以及刺座型態、斑紋等變化的品種，國際間相當具有知名度。通常6年株齡以上才能開花，在暖季會不定期開花。

The spineless cactus with a lovely appearance appeals to collectors. Variants with different numbers of ribs, shapes of areoles and stripe patterns are available in the market, also well-known worldwide. It usually takes more than 6 years to bloom, flowering sporadically in warm seasons.